diff --git a/tests/test_ssl.py b/tests/test_ssl.py
index 14b2310..d2a56b7 100644
--- a/tests/test_ssl.py
+++ b/tests/test_ssl.py
@@ -15,7 +15,7 @@
 from os import makedirs
 from os.path import join
 from weakref import ref
-from warnings import catch_warnings, simplefilter
+from warnings import simplefilter
 
 import pytest
 
@@ -81,8 +81,7 @@
 except ImportError:
     SSL_ST_INIT = SSL_ST_BEFORE = SSL_ST_OK = SSL_ST_RENEGOTIATE = None
 
-from .util import (
-    WARNING_TYPE_EXPECTED, NON_ASCII, TestCase, is_consistent_type)
+from .util import WARNING_TYPE_EXPECTED, NON_ASCII, is_consistent_type
 from .test_crypto import (
     cleartextCertificatePEM, cleartextPrivateKeyPEM,
     client_cert_pem, client_key_pem, server_cert_pem, server_key_pem,
@@ -222,28 +221,6 @@
     return [(cakey, cacert), (ikey, icert), (skey, scert)]
 
 
-class _LoopbackMixin(object):
-    """
-    Helper mixin which defines methods for creating a connected socket pair and
-    for forcing two connected SSL sockets to talk to each other via memory
-    BIOs.
-    """
-    def _loopbackClientFactory(self, socket):
-        return loopback_client_factory(socket)
-
-    def _loopbackServerFactory(self, socket):
-        return loopback_server_factory(socket)
-
-    def _loopback(self, serverFactory=None, clientFactory=None):
-        return loopback(serverFactory, clientFactory)
-
-    def _interactInMemory(self, client_conn, server_conn):
-        return interact_in_memory(client_conn, server_conn)
-
-    def _handshakeInMemory(self, client_conn, server_conn):
-        return handshake_in_memory(client_conn, server_conn)
-
-
 def loopback_client_factory(socket):
     client = Connection(Context(TLSv1_METHOD), socket)
     client.set_connect_state()
@@ -342,32 +319,30 @@
     interact_in_memory(client_conn, server_conn)
 
 
-class VersionTests(TestCase):
+class TestVersion(object):
     """
-    Tests for version information exposed by
-    :py:obj:`OpenSSL.SSL.SSLeay_version` and
-    :py:obj:`OpenSSL.SSL.OPENSSL_VERSION_NUMBER`.
+    Tests for version information exposed by `OpenSSL.SSL.SSLeay_version` and
+    `OpenSSL.SSL.OPENSSL_VERSION_NUMBER`.
     """
     def test_OPENSSL_VERSION_NUMBER(self):
         """
-        :py:obj:`OPENSSL_VERSION_NUMBER` is an integer with status in the low
-        byte and the patch, fix, minor, and major versions in the
-        nibbles above that.
+        `OPENSSL_VERSION_NUMBER` is an integer with status in the low byte and
+        the patch, fix, minor, and major versions in the nibbles above that.
         """
-        self.assertTrue(isinstance(OPENSSL_VERSION_NUMBER, int))
+        assert isinstance(OPENSSL_VERSION_NUMBER, int)
 
     def test_SSLeay_version(self):
         """
-        :py:obj:`SSLeay_version` takes a version type indicator and returns
-        one of a number of version strings based on that indicator.
+        `SSLeay_version` takes a version type indicator and returns one of a
+        number of version strings based on that indicator.
         """
         versions = {}
         for t in [SSLEAY_VERSION, SSLEAY_CFLAGS, SSLEAY_BUILT_ON,
                   SSLEAY_PLATFORM, SSLEAY_DIR]:
             version = SSLeay_version(t)
             versions[version] = t
-            self.assertTrue(isinstance(version, bytes))
-        self.assertEqual(len(versions), 5)
+            assert isinstance(version, bytes)
+        assert len(versions) == 5
 
 
 @pytest.fixture
@@ -2671,97 +2646,84 @@
         assert 2 == len(data)
 
 
-class ConnectionGetCipherListTests(TestCase):
+class TestConnectionGetCipherList(object):
     """
-    Tests for :py:obj:`Connection.get_cipher_list`.
+    Tests for `Connection.get_cipher_list`.
     """
-    def test_wrong_args(self):
-        """
-        :py:obj:`Connection.get_cipher_list` raises :py:obj:`TypeError` if
-        called with any arguments.
-        """
-        connection = Connection(Context(TLSv1_METHOD), None)
-        self.assertRaises(TypeError, connection.get_cipher_list, None)
-
     def test_result(self):
         """
-        :py:obj:`Connection.get_cipher_list` returns a :py:obj:`list` of
-        :py:obj:`bytes` giving the names of the ciphers which might be used.
+        `Connection.get_cipher_list` returns a list of `bytes` giving the
+        names of the ciphers which might be used.
         """
         connection = Connection(Context(TLSv1_METHOD), None)
         ciphers = connection.get_cipher_list()
-        self.assertTrue(isinstance(ciphers, list))
+        assert isinstance(ciphers, list)
         for cipher in ciphers:
-            self.assertTrue(isinstance(cipher, str))
+            assert isinstance(cipher, str)
 
 
-class ConnectionSendTests(TestCase, _LoopbackMixin):
+class TestConnectionSend(object):
     """
-    Tests for :py:obj:`Connection.send`
+    Tests for `Connection.send`.
     """
     def test_wrong_args(self):
         """
         When called with arguments other than string argument for its first
-        parameter or more than two arguments, :py:obj:`Connection.send` raises
-        :py:obj:`TypeError`.
+        parameter, `Connection.send` raises `TypeError`.
         """
         connection = Connection(Context(TLSv1_METHOD), None)
-        self.assertRaises(TypeError, connection.send)
-        self.assertRaises(TypeError, connection.send, object())
-        self.assertRaises(TypeError, connection.send, "foo", object(), "bar")
+        with pytest.raises(TypeError):
+            connection.send(object())
 
     def test_short_bytes(self):
         """
-        When passed a short byte string, :py:obj:`Connection.send` transmits
-        all of it and returns the number of bytes sent.
+        When passed a short byte string, `Connection.send` transmits all of it
+        and returns the number of bytes sent.
         """
-        server, client = self._loopback()
+        server, client = loopback()
         count = server.send(b'xy')
-        self.assertEquals(count, 2)
-        self.assertEquals(client.recv(2), b'xy')
+        assert count == 2
+        assert client.recv(2) == b'xy'
 
     def test_text(self):
         """
-        When passed a text, :py:obj:`Connection.send` transmits all of it and
+        When passed a text, `Connection.send` transmits all of it and
         returns the number of bytes sent. It also raises a DeprecationWarning.
         """
-        server, client = self._loopback()
-        with catch_warnings(record=True) as w:
+        server, client = loopback()
+        with pytest.warns(DeprecationWarning) as w:
             simplefilter("always")
             count = server.send(b"xy".decode("ascii"))
-            self.assertEqual(
+            assert (
                 "{0} for buf is no longer accepted, use bytes".format(
                     WARNING_TYPE_EXPECTED
-                ),
-                str(w[-1].message)
-            )
-            self.assertIs(w[-1].category, DeprecationWarning)
-        self.assertEquals(count, 2)
-        self.assertEquals(client.recv(2), b"xy")
+                ) == str(w[-1].message))
+        assert count == 2
+        assert client.recv(2) == b'xy'
 
     @skip_if_py26
     def test_short_memoryview(self):
         """
         When passed a memoryview onto a small number of bytes,
-        :py:obj:`Connection.send` transmits all of them and returns the number
+        `Connection.send` transmits all of them and returns the number
         of bytes sent.
         """
-        server, client = self._loopback()
+        server, client = loopback()
         count = server.send(memoryview(b'xy'))
-        self.assertEquals(count, 2)
-        self.assertEquals(client.recv(2), b'xy')
+        assert count == 2
+        assert client.recv(2) == b'xy'
 
     @skip_if_py3
     def test_short_buffer(self):
         """
         When passed a buffer containing a small number of bytes,
-        :py:obj:`Connection.send` transmits all of them and returns the number
+        `Connection.send` transmits all of them and returns the number
         of bytes sent.
         """
-        server, client = self._loopback()
+        server, client = loopback()
         count = server.send(buffer(b'xy'))
-        self.assertEquals(count, 2)
-        self.assertEquals(client.recv(2), b'xy')
+        assert count == 2
+        assert client.recv(2) == b'xy'
 
 
 def _make_memoryview(size):
@@ -2772,52 +2734,50 @@
     return memoryview(bytearray(size))
 
 
-class ConnectionRecvIntoTests(TestCase, _LoopbackMixin):
+class TestConnectionRecvInto(object):
     """
-    Tests for :py:obj:`Connection.recv_into`
+    Tests for `Connection.recv_into`.
     """
     def _no_length_test(self, factory):
         """
-        Assert that when the given buffer is passed to
-        ``Connection.recv_into``, whatever bytes are available to be received
-        that fit into that buffer are written into that buffer.
+        Assert that when the given buffer is passed to `Connection.recv_into`,
+        whatever bytes are available to be received that fit into that buffer
+        are written into that buffer.
         """
         output_buffer = factory(5)
 
-        server, client = self._loopback()
+        server, client = loopback()
         server.send(b'xy')
 
-        self.assertEqual(client.recv_into(output_buffer), 2)
-        self.assertEqual(output_buffer, bytearray(b'xy\x00\x00\x00'))
+        assert client.recv_into(output_buffer) == 2
+        assert output_buffer == bytearray(b'xy\x00\x00\x00')
 
     def test_bytearray_no_length(self):
         """
-        :py:obj:`Connection.recv_into` can be passed a ``bytearray`` instance
-        and data in the receive buffer is written to it.
+        `Connection.recv_into` can be passed a `bytearray` instance and data
+        in the receive buffer is written to it.
         """
         self._no_length_test(bytearray)
 
     def _respects_length_test(self, factory):
         """
-        Assert that when the given buffer is passed to ``Connection.recv_into``
-        along with a value for ``nbytes`` that is less than the size of that
-        buffer, only ``nbytes`` bytes are written into the buffer.
+        Assert that when the given buffer is passed to `Connection.recv_into`
+        along with a value for `nbytes` that is less than the size of that
+        buffer, only `nbytes` bytes are written into the buffer.
         """
         output_buffer = factory(10)
 
-        server, client = self._loopback()
+        server, client = loopback()
         server.send(b'abcdefghij')
 
-        self.assertEqual(client.recv_into(output_buffer, 5), 5)
-        self.assertEqual(
-            output_buffer, bytearray(b'abcde\x00\x00\x00\x00\x00')
-        )
+        assert client.recv_into(output_buffer, 5) == 5
+        assert output_buffer == bytearray(b'abcde\x00\x00\x00\x00\x00')
 
     def test_bytearray_respects_length(self):
         """
-        When called with a ``bytearray`` instance,
-        :py:obj:`Connection.recv_into` respects the ``nbytes`` parameter and
-        doesn't copy in more than that number of bytes.
+        When called with a `bytearray` instance, `Connection.recv_into`
+        respects the `nbytes` parameter and doesn't copy in more than that
+        number of bytes.
         """
         self._respects_length_test(bytearray)
 
@@ -2825,153 +2785,144 @@
         """
         Assert that if there are more bytes available to be read from the
         receive buffer than would fit into the buffer passed to
-        :py:obj:`Connection.recv_into`, only as many as fit are written into
-        it.
+        `Connection.recv_into`, only as many as fit are written into it.
         """
         output_buffer = factory(5)
 
-        server, client = self._loopback()
+        server, client = loopback()
         server.send(b'abcdefghij')
 
-        self.assertEqual(client.recv_into(output_buffer), 5)
-        self.assertEqual(output_buffer, bytearray(b'abcde'))
+        assert client.recv_into(output_buffer) == 5
+        assert output_buffer == bytearray(b'abcde')
         rest = client.recv(5)
-        self.assertEqual(b'fghij', rest)
+        assert b'fghij' == rest
 
     def test_bytearray_doesnt_overfill(self):
         """
-        When called with a ``bytearray`` instance,
-        :py:obj:`Connection.recv_into` respects the size of the array and
-        doesn't write more bytes into it than will fit.
+        When called with a `bytearray` instance, `Connection.recv_into`
+        respects the size of the array and doesn't write more bytes into it
+        than will fit.
         """
         self._doesnt_overfill_test(bytearray)
 
     def test_bytearray_really_doesnt_overfill(self):
         """
-        When called with a ``bytearray`` instance and an ``nbytes`` value that
-        is too large, :py:obj:`Connection.recv_into` respects the size of the
-        array and not the ``nbytes`` value and doesn't write more bytes into
-        the buffer than will fit.
+        When called with a `bytearray` instance and an `nbytes` value that is
+        too large, `Connection.recv_into` respects the size of the array and
+        not the `nbytes` value and doesn't write more bytes into the buffer
+        than will fit.
         """
         self._doesnt_overfill_test(bytearray)
 
     def test_peek(self):
-        server, client = self._loopback()
+        server, client = loopback()
         server.send(b'xy')
 
         for _ in range(2):
             output_buffer = bytearray(5)
-            self.assertEqual(
-                client.recv_into(output_buffer, flags=MSG_PEEK), 2)
-            self.assertEqual(output_buffer, bytearray(b'xy\x00\x00\x00'))
+            assert client.recv_into(output_buffer, flags=MSG_PEEK) == 2
+            assert output_buffer == bytearray(b'xy\x00\x00\x00')
 
     @skip_if_py26
     def test_memoryview_no_length(self):
         """
-        :py:obj:`Connection.recv_into` can be passed a ``memoryview``
-        instance and data in the receive buffer is written to it.
+        `Connection.recv_into` can be passed a `memoryview` instance and data
+        in the receive buffer is written to it.
         """
         self._no_length_test(_make_memoryview)
 
     @skip_if_py26
     def test_memoryview_respects_length(self):
         """
-        When called with a ``memoryview`` instance,
-        :py:obj:`Connection.recv_into` respects the ``nbytes`` parameter
-        and doesn't copy more than that number of bytes in.
+        When called with a `memoryview` instance, `Connection.recv_into`
+        respects the ``nbytes`` parameter and doesn't copy more than that
+        number of bytes in.
         """
         self._respects_length_test(_make_memoryview)
 
     @skip_if_py26
     def test_memoryview_doesnt_overfill(self):
         """
-        When called with a ``memoryview`` instance,
-        :py:obj:`Connection.recv_into` respects the size of the array and
-        doesn't write more bytes into it than will fit.
+        When called with a `memoryview` instance, `Connection.recv_into`
+        respects the size of the array and doesn't write more bytes into it
+        than will fit.
         """
         self._doesnt_overfill_test(_make_memoryview)
 
     @skip_if_py26
     def test_memoryview_really_doesnt_overfill(self):
         """
-        When called with a ``memoryview`` instance and an ``nbytes`` value
-        that is too large, :py:obj:`Connection.recv_into` respects the size
-        of the array and not the ``nbytes`` value and doesn't write more
-        bytes into the buffer than will fit.
+        When called with a `memoryview` instance and an `nbytes` value that is
+        too large, `Connection.recv_into` respects the size of the array and
+        not the `nbytes` value and doesn't write more bytes into the buffer
+        than will fit.
         """
         self._doesnt_overfill_test(_make_memoryview)
 
 
-class ConnectionSendallTests(TestCase, _LoopbackMixin):
+class TestConnectionSendall(object):
     """
-    Tests for :py:obj:`Connection.sendall`.
+    Tests for `Connection.sendall`.
     """
     def test_wrong_args(self):
         """
         When called with arguments other than a string argument for its first
-        parameter or with more than two arguments, :py:obj:`Connection.sendall`
-        raises :py:obj:`TypeError`.
+        parameter, `Connection.sendall` raises `TypeError`.
         """
         connection = Connection(Context(TLSv1_METHOD), None)
-        self.assertRaises(TypeError, connection.sendall)
-        self.assertRaises(TypeError, connection.sendall, object())
-        self.assertRaises(
-            TypeError, connection.sendall, "foo", object(), "bar")
+        with pytest.raises(TypeError):
+            connection.sendall(object())
 
     def test_short(self):
         """
-        :py:obj:`Connection.sendall` transmits all of the bytes in the string
+        `Connection.sendall` transmits all of the bytes in the string
         passed to it.
         """
-        server, client = self._loopback()
+        server, client = loopback()
         server.sendall(b'x')
-        self.assertEquals(client.recv(1), b'x')
+        assert client.recv(1) == b'x'
 
     def test_text(self):
         """
-        :py:obj:`Connection.sendall` transmits all the content in the string
-        passed to it raising a DeprecationWarning in case of this being a text.
+        `Connection.sendall` transmits all the content in the string passed
+        to it, raising a DeprecationWarning in case of this being a text.
         """
-        server, client = self._loopback()
-        with catch_warnings(record=True) as w:
+        server, client = loopback()
+        with pytest.warns(DeprecationWarning) as w:
             simplefilter("always")
             server.sendall(b"x".decode("ascii"))
-            self.assertEqual(
+            assert (
                 "{0} for buf is no longer accepted, use bytes".format(
                     WARNING_TYPE_EXPECTED
-                ),
-                str(w[-1].message)
-            )
-            self.assertIs(w[-1].category, DeprecationWarning)
-        self.assertEquals(client.recv(1), b"x")
+                ) == str(w[-1].message))
+        assert client.recv(1) == b"x"
 
     @skip_if_py26
     def test_short_memoryview(self):
         """
         When passed a memoryview onto a small number of bytes,
-        :py:obj:`Connection.sendall` transmits all of them.
+        `Connection.sendall` transmits all of them.
         """
-        server, client = self._loopback()
+        server, client = loopback()
         server.sendall(memoryview(b'x'))
-        self.assertEquals(client.recv(1), b'x')
+        assert client.recv(1) == b'x'
 
     @skip_if_py3
     def test_short_buffers(self):
         """
         When passed a buffer containing a small number of bytes,
-        :py:obj:`Connection.sendall` transmits all of them.
+        `Connection.sendall` transmits all of them.
         """
-        server, client = self._loopback()
+        server, client = loopback()
         server.sendall(buffer(b'x'))
-        self.assertEquals(client.recv(1), b'x')
+        assert client.recv(1) == b'x'
 
     def test_long(self):
         """
-        :py:obj:`Connection.sendall` transmits all of the bytes in the string
-        passed to it even if this requires multiple calls of an underlying
-        write function.
+        `Connection.sendall` transmits all the bytes in the string passed to it
+        even if this requires multiple calls of an underlying write function.
         """
-        server, client = self._loopback()
+        server, client = loopback()
         # Should be enough, underlying SSL_write should only do 16k at a time.
         # On Windows, after 32k of bytes the write will block (forever
         # - because no one is yet reading).
@@ -2983,55 +2934,40 @@
             data = client.recv(1024)
             accum.append(data)
             received += len(data)
-        self.assertEquals(message, b''.join(accum))
+        assert message == b''.join(accum)
 
     def test_closed(self):
         """
-        If the underlying socket is closed, :py:obj:`Connection.sendall`
-        propagates the write error from the low level write call.
+        If the underlying socket is closed, `Connection.sendall` propagates the
+        write error from the low level write call.
         """
-        server, client = self._loopback()
+        server, client = loopback()
         server.sock_shutdown(2)
-        exc = self.assertRaises(SysCallError, server.sendall, b"hello, world")
+        with pytest.raises(SysCallError) as err:
+            server.sendall(b"hello, world")
         if platform == "win32":
-            self.assertEqual(exc.args[0], ESHUTDOWN)
+            assert err.value.args[0] == ESHUTDOWN
         else:
-            self.assertEqual(exc.args[0], EPIPE)
+            assert err.value.args[0] == EPIPE
 
 
-class ConnectionRenegotiateTests(TestCase, _LoopbackMixin):
+class TestConnectionRenegotiate(object):
     """
     Tests for SSL renegotiation APIs.
     """
-    def test_renegotiate_wrong_args(self):
-        """
-        :py:obj:`Connection.renegotiate` raises :py:obj:`TypeError` if called
-        with any arguments.
-        """
-        connection = Connection(Context(TLSv1_METHOD), None)
-        self.assertRaises(TypeError, connection.renegotiate, None)
-
-    def test_total_renegotiations_wrong_args(self):
-        """
-        :py:obj:`Connection.total_renegotiations` raises :py:obj:`TypeError` if
-        called with any arguments.
-        """
-        connection = Connection(Context(TLSv1_METHOD), None)
-        self.assertRaises(TypeError, connection.total_renegotiations, None)
-
     def test_total_renegotiations(self):
         """
-        :py:obj:`Connection.total_renegotiations` returns :py:obj:`0` before
-        any renegotiations have happened.
+        `Connection.total_renegotiations` returns `0` before any renegotiations
+        have happened.
         """
         connection = Connection(Context(TLSv1_METHOD), None)
-        self.assertEquals(connection.total_renegotiations(), 0)
+        assert connection.total_renegotiations() == 0
 
     def test_renegotiate(self):
         """
         Go through a complete renegotiation cycle.
         """
-        server, client = self._loopback()
+        server, client = loopback()
 
         server.send(b"hello world")
 
@@ -3055,21 +2991,21 @@
             pass
 
 
-class ErrorTests(TestCase):
+class TestError(object):
     """
-    Unit tests for :py:obj:`OpenSSL.SSL.Error`.
+    Unit tests for `OpenSSL.SSL.Error`.
     """
     def test_type(self):
         """
-        :py:obj:`Error` is an exception type.
+        `Error` is an exception type.
         """
-        self.assertTrue(issubclass(Error, Exception))
-        self.assertEqual(Error.__name__, 'Error')
+        assert issubclass(Error, Exception)
+        assert Error.__name__ == 'Error'
 
 
-class ConstantsTests(TestCase):
+class TestConstants(object):
     """
-    Tests for the values of constants exposed in :py:obj:`OpenSSL.SSL`.
+    Tests for the values of constants exposed in `OpenSSL.SSL`.
 
     These are values defined by OpenSSL intended only to be used as flags to
     OpenSSL APIs.  The only assertions it seems can be made about them is
@@ -3081,10 +3017,10 @@
     )
     def test_op_no_query_mtu(self):
         """
-        The value of :py:obj:`OpenSSL.SSL.OP_NO_QUERY_MTU` is 0x1000, the value
-        of :py:const:`SSL_OP_NO_QUERY_MTU` defined by :file:`openssl/ssl.h`.
+        The value of `OpenSSL.SSL.OP_NO_QUERY_MTU` is 0x1000, the value
+        of `SSL_OP_NO_QUERY_MTU` defined by `openssl/ssl.h`.
         """
-        self.assertEqual(OP_NO_QUERY_MTU, 0x1000)
+        assert OP_NO_QUERY_MTU == 0x1000
 
     @pytest.mark.skipif(
         OP_COOKIE_EXCHANGE is None,
@@ -3093,11 +3029,10 @@
     )
     def test_op_cookie_exchange(self):
         """
-        The value of :py:obj:`OpenSSL.SSL.OP_COOKIE_EXCHANGE` is 0x2000, the
-        value of :py:const:`SSL_OP_COOKIE_EXCHANGE` defined by
-        :file:`openssl/ssl.h`.
+        The value of `OpenSSL.SSL.OP_COOKIE_EXCHANGE` is 0x2000, the
+        value of `SSL_OP_COOKIE_EXCHANGE` defined by `openssl/ssl.h`.
         """
-        self.assertEqual(OP_COOKIE_EXCHANGE, 0x2000)
+        assert OP_COOKIE_EXCHANGE == 0x2000
 
     @pytest.mark.skipif(
         OP_NO_TICKET is None,
@@ -3105,10 +3040,10 @@
     )
     def test_op_no_ticket(self):
         """
-        The value of :py:obj:`OpenSSL.SSL.OP_NO_TICKET` is 0x4000, the value of
-        :py:const:`SSL_OP_NO_TICKET` defined by :file:`openssl/ssl.h`.
+        The value of `OpenSSL.SSL.OP_NO_TICKET` is 0x4000, the value of
+        `SSL_OP_NO_TICKET` defined by `openssl/ssl.h`.
         """
-        self.assertEqual(OP_NO_TICKET, 0x4000)
+        assert OP_NO_TICKET == 0x4000
 
     @pytest.mark.skipif(
         OP_NO_COMPRESSION is None,
@@ -3116,81 +3051,79 @@
     )
     def test_op_no_compression(self):
         """
-        The value of :py:obj:`OpenSSL.SSL.OP_NO_COMPRESSION` is 0x20000, the
-        value of :py:const:`SSL_OP_NO_COMPRESSION` defined by
-        :file:`openssl/ssl.h`.
+        The value of `OpenSSL.SSL.OP_NO_COMPRESSION` is 0x20000, the
+        value of `SSL_OP_NO_COMPRESSION` defined by `openssl/ssl.h`.
         """
-        self.assertEqual(OP_NO_COMPRESSION, 0x20000)
+        assert OP_NO_COMPRESSION == 0x20000
 
     def test_sess_cache_off(self):
         """
-        The value of :py:obj:`OpenSSL.SSL.SESS_CACHE_OFF` 0x0, the value of
-        :py:obj:`SSL_SESS_CACHE_OFF` defined by ``openssl/ssl.h``.
+        The value of `OpenSSL.SSL.SESS_CACHE_OFF` 0x0, the value of
+        `SSL_SESS_CACHE_OFF` defined by `openssl/ssl.h`.
         """
-        self.assertEqual(0x0, SESS_CACHE_OFF)
+        assert 0x0 == SESS_CACHE_OFF
 
     def test_sess_cache_client(self):
         """
-        The value of :py:obj:`OpenSSL.SSL.SESS_CACHE_CLIENT` 0x1, the value of
-        :py:obj:`SSL_SESS_CACHE_CLIENT` defined by ``openssl/ssl.h``.
+        The value of `OpenSSL.SSL.SESS_CACHE_CLIENT` 0x1, the value of
+        `SSL_SESS_CACHE_CLIENT` defined by `openssl/ssl.h`.
         """
-        self.assertEqual(0x1, SESS_CACHE_CLIENT)
+        assert 0x1 == SESS_CACHE_CLIENT
 
     def test_sess_cache_server(self):
         """
-        The value of :py:obj:`OpenSSL.SSL.SESS_CACHE_SERVER` 0x2, the value of
-        :py:obj:`SSL_SESS_CACHE_SERVER` defined by ``openssl/ssl.h``.
+        The value of `OpenSSL.SSL.SESS_CACHE_SERVER` 0x2, the value of
+        `SSL_SESS_CACHE_SERVER` defined by `openssl/ssl.h`.
         """
-        self.assertEqual(0x2, SESS_CACHE_SERVER)
+        assert 0x2 == SESS_CACHE_SERVER
 
     def test_sess_cache_both(self):
         """
-        The value of :py:obj:`OpenSSL.SSL.SESS_CACHE_BOTH` 0x3, the value of
-        :py:obj:`SSL_SESS_CACHE_BOTH` defined by ``openssl/ssl.h``.
+        The value of `OpenSSL.SSL.SESS_CACHE_BOTH` 0x3, the value of
+        `SSL_SESS_CACHE_BOTH` defined by `openssl/ssl.h`.
         """
-        self.assertEqual(0x3, SESS_CACHE_BOTH)
+        assert 0x3 == SESS_CACHE_BOTH
 
     def test_sess_cache_no_auto_clear(self):
         """
-        The value of :py:obj:`OpenSSL.SSL.SESS_CACHE_NO_AUTO_CLEAR` 0x80, the
-        value of :py:obj:`SSL_SESS_CACHE_NO_AUTO_CLEAR` defined by
-        ``openssl/ssl.h``.
+        The value of `OpenSSL.SSL.SESS_CACHE_NO_AUTO_CLEAR` 0x80, the
+        value of `SSL_SESS_CACHE_NO_AUTO_CLEAR` defined by
+        `openssl/ssl.h`.
         """
-        self.assertEqual(0x80, SESS_CACHE_NO_AUTO_CLEAR)
+        assert 0x80 == SESS_CACHE_NO_AUTO_CLEAR
 
     def test_sess_cache_no_internal_lookup(self):
         """
-        The value of :py:obj:`OpenSSL.SSL.SESS_CACHE_NO_INTERNAL_LOOKUP` 0x100,
-        the value of :py:obj:`SSL_SESS_CACHE_NO_INTERNAL_LOOKUP` defined by
-        ``openssl/ssl.h``.
+        The value of `OpenSSL.SSL.SESS_CACHE_NO_INTERNAL_LOOKUP` 0x100,
+        the value of `SSL_SESS_CACHE_NO_INTERNAL_LOOKUP` defined by
+        `openssl/ssl.h`.
         """
-        self.assertEqual(0x100, SESS_CACHE_NO_INTERNAL_LOOKUP)
+        assert 0x100 == SESS_CACHE_NO_INTERNAL_LOOKUP
 
     def test_sess_cache_no_internal_store(self):
         """
-        The value of :py:obj:`OpenSSL.SSL.SESS_CACHE_NO_INTERNAL_STORE` 0x200,
-        the value of :py:obj:`SSL_SESS_CACHE_NO_INTERNAL_STORE` defined by
-        ``openssl/ssl.h``.
+        The value of `OpenSSL.SSL.SESS_CACHE_NO_INTERNAL_STORE` 0x200,
+        the value of `SSL_SESS_CACHE_NO_INTERNAL_STORE` defined by
+        `openssl/ssl.h`.
         """
-        self.assertEqual(0x200, SESS_CACHE_NO_INTERNAL_STORE)
+        assert 0x200 == SESS_CACHE_NO_INTERNAL_STORE
 
     def test_sess_cache_no_internal(self):
         """
-        The value of :py:obj:`OpenSSL.SSL.SESS_CACHE_NO_INTERNAL` 0x300, the
-        value of :py:obj:`SSL_SESS_CACHE_NO_INTERNAL` defined by
-        ``openssl/ssl.h``.
+        The value of `OpenSSL.SSL.SESS_CACHE_NO_INTERNAL` 0x300, the
+        value of `SSL_SESS_CACHE_NO_INTERNAL` defined by
+        `openssl/ssl.h`.
         """
-        self.assertEqual(0x300, SESS_CACHE_NO_INTERNAL)
+        assert 0x300 == SESS_CACHE_NO_INTERNAL
 
 
-class MemoryBIOTests(TestCase, _LoopbackMixin):
+class TestMemoryBIO(object):
     """
-    Tests for :py:obj:`OpenSSL.SSL.Connection` using a memory BIO.
+    Tests for `OpenSSL.SSL.Connection` using a memory BIO.
     """
     def _server(self, sock):
         """
-        Create a new server-side SSL :py:obj:`Connection` object wrapped around
-        :py:obj:`sock`.
+        Create a new server-side SSL `Connection` object wrapped around `sock`.
         """
         # Create the server side Connection.  This is mostly setup boilerplate
         # - use TLSv1, use a particular certificate, etc.
@@ -3215,8 +3148,7 @@
 
     def _client(self, sock):
         """
-        Create a new client-side SSL :py:obj:`Connection` object wrapped around
-        :py:obj:`sock`.
+        Create a new client-side SSL `Connection` object wrapped around `sock`.
         """
         # Now create the client side Connection.  Similar boilerplate to the
         # above.
@@ -3237,179 +3169,178 @@
         client_conn.set_connect_state()
         return client_conn
 
-    def test_memoryConnect(self):
+    def test_memory_connect(self):
         """
-        Two :py:obj:`Connection`s which use memory BIOs can be manually
-        connected by reading from the output of each and writing those bytes to
-        the input of the other and in this way establish a connection and
-        exchange application-level bytes with each other.
+        Two `Connection`s which use memory BIOs can be manually connected by
+        reading from the output of each and writing those bytes to the input of
+        the other and in this way establish a connection and exchange
+        application-level bytes with each other.
         """
         server_conn = self._server(None)
         client_conn = self._client(None)
 
         # There should be no key or nonces yet.
-        self.assertIdentical(server_conn.master_key(), None)
-        self.assertIdentical(server_conn.client_random(), None)
-        self.assertIdentical(server_conn.server_random(), None)
+        assert server_conn.master_key() is None
+        assert server_conn.client_random() is None
+        assert server_conn.server_random() is None
 
         # First, the handshake needs to happen.  We'll deliver bytes back and
         # forth between the client and server until neither of them feels like
         # speaking any more.
-        self.assertIdentical(
-            self._interactInMemory(client_conn, server_conn), None)
+        assert interact_in_memory(client_conn, server_conn) is None
 
         # Now that the handshake is done, there should be a key and nonces.
-        self.assertNotIdentical(server_conn.master_key(), None)
-        self.assertNotIdentical(server_conn.client_random(), None)
-        self.assertNotIdentical(server_conn.server_random(), None)
-        self.assertEquals(
-            server_conn.client_random(), client_conn.client_random())
-        self.assertEquals(
-            server_conn.server_random(), client_conn.server_random())
-        self.assertNotEquals(
-            server_conn.client_random(), server_conn.server_random())
-        self.assertNotEquals(
-            client_conn.client_random(), client_conn.server_random())
+        assert server_conn.master_key() is not None
+        assert server_conn.client_random() is not None
+        assert server_conn.server_random() is not None
+        assert server_conn.client_random() == client_conn.client_random()
+        assert server_conn.server_random() == client_conn.server_random()
+        assert server_conn.client_random() != server_conn.server_random()
+        assert client_conn.client_random() != client_conn.server_random()
 
         # Here are the bytes we'll try to send.
         important_message = b'One if by land, two if by sea.'
 
         server_conn.write(important_message)
-        self.assertEquals(
-            self._interactInMemory(client_conn, server_conn),
+        assert (
+            interact_in_memory(client_conn, server_conn) ==
             (client_conn, important_message))
 
         client_conn.write(important_message[::-1])
-        self.assertEquals(
-            self._interactInMemory(client_conn, server_conn),
+        assert (
+            interact_in_memory(client_conn, server_conn) ==
             (server_conn, important_message[::-1]))
 
-    def test_socketConnect(self):
+    def test_socket_connect(self):
         """
-        Just like :py:obj:`test_memoryConnect` but with an actual socket.
+        Just like `test_memory_connect` but with an actual socket.
 
         This is primarily to rule out the memory BIO code as the source of any
-        problems encountered while passing data over a :py:obj:`Connection` (if
+        problems encountered while passing data over a `Connection` (if
         this test fails, there must be a problem outside the memory BIO code,
         as no memory BIO is involved here).  Even though this isn't a memory
         BIO test, it's convenient to have it here.
         """
-        server_conn, client_conn = self._loopback()
+        server_conn, client_conn = loopback()
 
         important_message = b"Help me Obi Wan Kenobi, you're my only hope."
         client_conn.send(important_message)
         msg = server_conn.recv(1024)
-        self.assertEqual(msg, important_message)
+        assert msg == important_message
 
         # Again in the other direction, just for fun.
         important_message = important_message[::-1]
         server_conn.send(important_message)
         msg = client_conn.recv(1024)
-        self.assertEqual(msg, important_message)
+        assert msg == important_message
 
-    def test_socketOverridesMemory(self):
+    def test_socket_overrides_memory(self):
         """
-        Test that :py:obj:`OpenSSL.SSL.bio_read` and
-        :py:obj:`OpenSSL.SSL.bio_write` don't work on
-        :py:obj:`OpenSSL.SSL.Connection`() that use sockets.
+        Test that `OpenSSL.SSL.bio_read` and `OpenSSL.SSL.bio_write` don't
+        work on `OpenSSL.SSL.Connection`() that use sockets.
         """
         context = Context(TLSv1_METHOD)
         client = socket()
         clientSSL = Connection(context, client)
-        self.assertRaises(TypeError, clientSSL.bio_read, 100)
-        self.assertRaises(TypeError, clientSSL.bio_write, "foo")
-        self.assertRaises(TypeError, clientSSL.bio_shutdown)
+        with pytest.raises(TypeError):
+            clientSSL.bio_read(100)
+        with pytest.raises(TypeError):
+            clientSSL.bio_write("foo")
+        with pytest.raises(TypeError):
+            clientSSL.bio_shutdown()
 
-    def test_outgoingOverflow(self):
+    def test_outgoing_overflow(self):
         """
         If more bytes than can be written to the memory BIO are passed to
-        :py:obj:`Connection.send` at once, the number of bytes which were
-        written is returned and that many bytes from the beginning of the input
-        can be read from the other end of the connection.
+        `Connection.send` at once, the number of bytes which were written is
+        returned and that many bytes from the beginning of the input can be
+        read from the other end of the connection.
         """
         server = self._server(None)
         client = self._client(None)
 
-        self._interactInMemory(client, server)
+        interact_in_memory(client, server)
 
         size = 2 ** 15
         sent = client.send(b"x" * size)
         # Sanity check.  We're trying to test what happens when the entire
         # input can't be sent.  If the entire input was sent, this test is
         # meaningless.
-        self.assertTrue(sent < size)
+        assert sent < size
 
-        receiver, received = self._interactInMemory(client, server)
-        self.assertIdentical(receiver, server)
+        receiver, received = interact_in_memory(client, server)
+        assert receiver is server
 
         # We can rely on all of these bytes being received at once because
-        # _loopback passes 2 ** 16 to recv - more than 2 ** 15.
-        self.assertEquals(len(received), sent)
+        # loopback passes 2 ** 16 to recv - more than 2 ** 15.
+        assert len(received) == sent
 
     def test_shutdown(self):
         """
-        :py:obj:`Connection.bio_shutdown` signals the end of the data stream
-        from which the :py:obj:`Connection` reads.
+        `Connection.bio_shutdown` signals the end of the data stream
+        from which the `Connection` reads.
         """
         server = self._server(None)
         server.bio_shutdown()
-        e = self.assertRaises(Error, server.recv, 1024)
+        with pytest.raises(Error) as err:
+            server.recv(1024)
         # We don't want WantReadError or ZeroReturnError or anything - it's a
         # handshake failure.
-        assert type(e) in [Error, SysCallError]
+        assert type(err.value) in [Error, SysCallError]
 
-    def test_unexpectedEndOfFile(self):
+    def test_unexpected_EOF(self):
         """
         If the connection is lost before an orderly SSL shutdown occurs,
-        :py:obj:`OpenSSL.SSL.SysCallError` is raised with a message of
+        `OpenSSL.SSL.SysCallError` is raised with a message of
         "Unexpected EOF".
         """
-        server_conn, client_conn = self._loopback()
+        server_conn, client_conn = loopback()
         client_conn.sock_shutdown(SHUT_RDWR)
-        exc = self.assertRaises(SysCallError, server_conn.recv, 1024)
-        self.assertEqual(exc.args, (-1, "Unexpected EOF"))
+        with pytest.raises(SysCallError) as err:
+            server_conn.recv(1024)
+        assert err.value.args == (-1, "Unexpected EOF")
 
     def _check_client_ca_list(self, func):
         """
-        Verify the return value of the :py:obj:`get_client_ca_list` method for
+        Verify the return value of the `get_client_ca_list` method for
         server and client connections.
 
         :param func: A function which will be called with the server context
             before the client and server are connected to each other.  This
             function should specify a list of CAs for the server to send to the
             client and return that same list.  The list will be used to verify
-            that :py:obj:`get_client_ca_list` returns the proper value at
+            that `get_client_ca_list` returns the proper value at
             various times.
         """
         server = self._server(None)
         client = self._client(None)
-        self.assertEqual(client.get_client_ca_list(), [])
-        self.assertEqual(server.get_client_ca_list(), [])
+        assert client.get_client_ca_list() == []
+        assert server.get_client_ca_list() == []
         ctx = server.get_context()
         expected = func(ctx)
-        self.assertEqual(client.get_client_ca_list(), [])
-        self.assertEqual(server.get_client_ca_list(), expected)
-        self._interactInMemory(client, server)
-        self.assertEqual(client.get_client_ca_list(), expected)
-        self.assertEqual(server.get_client_ca_list(), expected)
+        assert client.get_client_ca_list() == []
+        assert server.get_client_ca_list() == expected
+        interact_in_memory(client, server)
+        assert client.get_client_ca_list() == expected
+        assert server.get_client_ca_list() == expected
 
     def test_set_client_ca_list_errors(self):
         """
-        :py:obj:`Context.set_client_ca_list` raises a :py:obj:`TypeError` if
-        called with a non-list or a list that contains objects other than
-        X509Names.
+        `Context.set_client_ca_list` raises a `TypeError` if called with a
+        non-list or a list that contains objects other than X509Names.
         """
         ctx = Context(TLSv1_METHOD)
-        self.assertRaises(TypeError, ctx.set_client_ca_list, "spam")
-        self.assertRaises(TypeError, ctx.set_client_ca_list, ["spam"])
-        self.assertIdentical(ctx.set_client_ca_list([]), None)
+        with pytest.raises(TypeError):
+            ctx.set_client_ca_list("spam")
+        with pytest.raises(TypeError):
+            ctx.set_client_ca_list(["spam"])
 
     def test_set_empty_ca_list(self):
         """
-        If passed an empty list, :py:obj:`Context.set_client_ca_list`
-        configures the context to send no CA names to the client and, on both
-        the server and client sides, :py:obj:`Connection.get_client_ca_list`
-        returns an empty list after the connection is set up.
+        If passed an empty list, `Context.set_client_ca_list` configures the
+        context to send no CA names to the client and, on both the server and
+        client sides, `Connection.get_client_ca_list` returns an empty list
+        after the connection is set up.
         """
         def no_ca(ctx):
             ctx.set_client_ca_list([])
@@ -3419,9 +3350,9 @@
     def test_set_one_ca_list(self):
         """
         If passed a list containing a single X509Name,
-        :py:obj:`Context.set_client_ca_list` configures the context to send
+        `Context.set_client_ca_list` configures the context to send
         that CA name to the client and, on both the server and client sides,
-        :py:obj:`Connection.get_client_ca_list` returns a list containing that
+        `Connection.get_client_ca_list` returns a list containing that
         X509Name after the connection is set up.
         """
         cacert = load_certificate(FILETYPE_PEM, root_cert_pem)
@@ -3435,9 +3366,9 @@
     def test_set_multiple_ca_list(self):
         """
         If passed a list containing multiple X509Name objects,
-        :py:obj:`Context.set_client_ca_list` configures the context to send
+        `Context.set_client_ca_list` configures the context to send
         those CA names to the client and, on both the server and client sides,
-        :py:obj:`Connection.get_client_ca_list` returns a list containing those
+        `Connection.get_client_ca_list` returns a list containing those
         X509Names after the connection is set up.
         """
         secert = load_certificate(FILETYPE_PEM, server_cert_pem)
@@ -3455,7 +3386,7 @@
     def test_reset_ca_list(self):
         """
         If called multiple times, only the X509Names passed to the final call
-        of :py:obj:`Context.set_client_ca_list` are used to configure the CA
+        of `Context.set_client_ca_list` are used to configure the CA
         names sent to the client.
         """
         cacert = load_certificate(FILETYPE_PEM, root_cert_pem)
@@ -3474,7 +3405,7 @@
 
     def test_mutated_ca_list(self):
         """
-        If the list passed to :py:obj:`Context.set_client_ca_list` is mutated
+        If the list passed to `Context.set_client_ca_list` is mutated
         afterwards, this does not affect the list of CA names sent to the
         client.
         """
@@ -3491,21 +3422,19 @@
             return [cadesc]
         self._check_client_ca_list(mutated_ca)
 
-    def test_add_client_ca_errors(self):
+    def test_add_client_ca_wrong_args(self):
         """
-        :py:obj:`Context.add_client_ca` raises :py:obj:`TypeError` if called
-        with a non-X509 object or with a number of arguments other than one.
+        `Context.add_client_ca` raises `TypeError` if called with
+        a non-X509 object.
         """
         ctx = Context(TLSv1_METHOD)
-        cacert = load_certificate(FILETYPE_PEM, root_cert_pem)
-        self.assertRaises(TypeError, ctx.add_client_ca)
-        self.assertRaises(TypeError, ctx.add_client_ca, "spam")
-        self.assertRaises(TypeError, ctx.add_client_ca, cacert, cacert)
+        with pytest.raises(TypeError):
+            ctx.add_client_ca("spam")
 
     def test_one_add_client_ca(self):
         """
         A certificate's subject can be added as a CA to be sent to the client
-        with :py:obj:`Context.add_client_ca`.
+        with `Context.add_client_ca`.
         """
         cacert = load_certificate(FILETYPE_PEM, root_cert_pem)
         cadesc = cacert.get_subject()
@@ -3518,7 +3447,7 @@
     def test_multiple_add_client_ca(self):
         """
         Multiple CA names can be sent to the client by calling
-        :py:obj:`Context.add_client_ca` with multiple X509 objects.
+        `Context.add_client_ca` with multiple X509 objects.
         """
         cacert = load_certificate(FILETYPE_PEM, root_cert_pem)
         secert = load_certificate(FILETYPE_PEM, server_cert_pem)
@@ -3534,8 +3463,8 @@
 
     def test_set_and_add_client_ca(self):
         """
-        A call to :py:obj:`Context.set_client_ca_list` followed by a call to
-        :py:obj:`Context.add_client_ca` results in using the CA names from the
+        A call to `Context.set_client_ca_list` followed by a call to
+        `Context.add_client_ca` results in using the CA names from the
         first call and the CA name from the second call.
         """
         cacert = load_certificate(FILETYPE_PEM, root_cert_pem)
@@ -3554,8 +3483,8 @@
 
     def test_set_after_add_client_ca(self):
         """
-        A call to :py:obj:`Context.set_client_ca_list` after a call to
-        :py:obj:`Context.add_client_ca` replaces the CA name specified by the
+        A call to `Context.set_client_ca_list` after a call to
+        `Context.add_client_ca` replaces the CA name specified by the
         former call with the names specified by the latter call.
         """
         cacert = load_certificate(FILETYPE_PEM, root_cert_pem)
@@ -3573,7 +3502,7 @@
         self._check_client_ca_list(set_replaces_add_ca)
 
 
-class InfoConstantTests(TestCase):
+class TestInfoConstants(object):
     """
     Tests for assorted constants exposed for use in info callbacks.
     """
@@ -3642,7 +3571,7 @@
         assert results == []
 
 
-class TestOCSP(_LoopbackMixin):
+class TestOCSP(object):
     """
     Tests for PyOpenSSL's OCSP stapling support.
     """
@@ -3699,7 +3628,7 @@
             callback=ocsp_callback, data=None, request_ocsp=False
         )
         server = self._server_connection(callback=ocsp_callback, data=None)
-        self._handshakeInMemory(client, server)
+        handshake_in_memory(client, server)
 
         assert not called
 
@@ -3715,8 +3644,8 @@
             return True
 
         client = self._client_connection(callback=ocsp_callback, data=None)
-        server = self._loopbackServerFactory(socket=None)
-        self._handshakeInMemory(client, server)
+        server = loopback_server_factory(socket=None)
+        handshake_in_memory(client, server)
 
         assert len(called) == 1
         assert called[0] == b''
@@ -3736,7 +3665,7 @@
 
         client = self._client_connection(callback=client_callback, data=None)
         server = self._server_connection(callback=server_callback, data=None)
-        self._handshakeInMemory(client, server)
+        handshake_in_memory(client, server)
 
         assert len(calls) == 1
         assert calls[0] == self.sample_ocsp_data
@@ -3758,7 +3687,7 @@
 
         client = self._client_connection(callback=client_callback, data=None)
         server = self._server_connection(callback=server_callback, data=None)
-        self._handshakeInMemory(client, server)
+        handshake_in_memory(client, server)
 
         assert len(client_calls) == 1
         assert len(server_calls) == 1
@@ -3788,7 +3717,7 @@
         server = self._server_connection(
             callback=server_callback, data=sentinel
         )
-        self._handshakeInMemory(client, server)
+        handshake_in_memory(client, server)
 
         assert len(calls) == 2
         assert calls[0][-1] is sentinel
@@ -3810,7 +3739,7 @@
 
         client = self._client_connection(callback=client_callback, data=None)
         server = self._server_connection(callback=server_callback, data=None)
-        self._handshakeInMemory(client, server)
+        handshake_in_memory(client, server)
 
         assert len(client_calls) == 1
         assert client_calls[0] == b''
@@ -3829,7 +3758,7 @@
         server = self._server_connection(callback=server_callback, data=None)
 
         with pytest.raises(Error):
-            self._handshakeInMemory(client, server)
+            handshake_in_memory(client, server)
 
     def test_exceptions_in_client_bubble_up(self):
         """
@@ -3848,7 +3777,7 @@
         server = self._server_connection(callback=server_callback, data=None)
 
         with pytest.raises(SentinelException):
-            self._handshakeInMemory(client, server)
+            handshake_in_memory(client, server)
 
     def test_exceptions_in_server_bubble_up(self):
         """
@@ -3867,7 +3796,7 @@
         server = self._server_connection(callback=server_callback, data=None)
 
         with pytest.raises(SentinelException):
-            self._handshakeInMemory(client, server)
+            handshake_in_memory(client, server)
 
     def test_server_must_return_bytes(self):
         """
@@ -3883,4 +3812,4 @@
         server = self._server_connection(callback=server_callback, data=None)
 
         with pytest.raises(TypeError):
-            self._handshakeInMemory(client, server)
+            handshake_in_memory(client, server)
diff --git a/tests/util.py b/tests/util.py
index e1b8656..4464379 100644
--- a/tests/util.py
+++ b/tests/util.py
@@ -1,313 +1,18 @@
 # Copyright (C) Jean-Paul Calderone
 # Copyright (C) Twisted Matrix Laboratories.
 # See LICENSE for details.
-
 """
 Helpers for the OpenSSL test suite, largely copied from
 U{Twisted<http://twistedmatrix.com/>}.
 """
 
-import shutil
-import sys
-import traceback
-
-from tempfile import mktemp, mkdtemp
-from unittest import TestCase
-
-import pytest
-
 from six import PY3
 
-from OpenSSL._util import exception_from_error_queue
-from OpenSSL.crypto import Error
-
-
-from . import memdbg
-
-from OpenSSL._util import ffi, lib
-
 
 # This is the UTF-8 encoding of the SNOWMAN unicode code point.
 NON_ASCII = b"\xe2\x98\x83".decode("utf-8")
 
 
-class TestCase(TestCase):
-    """
-    :py:class:`TestCase` adds useful testing functionality beyond what is
-    available from the standard library :py:class:`unittest.TestCase`.
-    """
-
-    def run(self, result):
-        run = super(TestCase, self).run
-        if memdbg.heap is None:
-            return run(result)
-
-        # Run the test as usual
-        before = set(memdbg.heap)
-        run(result)
-
-        # Clean up some long-lived allocations so they won't be reported as
-        # memory leaks.
-        lib.CRYPTO_cleanup_all_ex_data()
-        lib.ERR_clear_error()
-        after = set(memdbg.heap)
-
-        if not after - before:
-            # No leaks, fast succeed
-            return
-
-        if result.wasSuccessful():
-            # If it passed, run it again with memory debugging
-            before = set(memdbg.heap)
-            run(result)
-
-            # Clean up some long-lived allocations so they won't be reported as
-            # memory leaks.
-            lib.CRYPTO_cleanup_all_ex_data()
-            lib.ERR_clear_error()
-
-            after = set(memdbg.heap)
-
-            self._reportLeaks(after - before, result)
-
-    def _reportLeaks(self, leaks, result):
-        def format_leak(p):
-            """
-            c_stack looks something like this (interesting parts indicated
-            with inserted arrows not part of the data):
-
-            cpython/2.7/python(PyCFunction_Call+0x8b) [0x56265a]
-            cpython/2.7/python() [0x4d5f52]
-            cpython/2.7/python(PyEval_EvalFrameEx+0x753b) [0x4d0e1e]
-            cpython/2.7/python() [0x4d6419]
-            cpython/2.7/python() [0x4d6129]
-            cpython/2.7/python(PyEval_EvalFrameEx+0x753b) [0x4d0e1e]
-            cpython/2.7/python(PyEval_EvalCodeEx+0x1043) [0x4d3726]
-            cpython/2.7/python() [0x55fd51]
-            cpython/2.7/python(PyObject_Call+0x7e) [0x420ee6]
-            cpython/2.7/python(PyEval_CallObjectWithKeywords+0x158) [0x4d56ec]
-            _cffi_backend.so(+0xe96e) [0x7fe2e38be96e]
-            libffi.so.6(ffi_closure_unix64_inner+0x1b9) [0x7fe2e36ad819]
-            libffi.so.6(ffi_closure_unix64+0x46) [0x7fe2e36adb7c]
-
-            |----- end interesting
-            v
-            libcrypto.so.1.0.0(CRYPTO_malloc+0x64) [0x7fe2e1cef784]
-            libcrypto.so.1.0.0(lh_insert+0x16b) [0x7fe2e1d6a24b]
-            libcrypto.so.1.0.0(+0x61c18) [0x7fe2e1cf0c18]
-            libcrypto.so.1.0.0(+0x625ec) [0x7fe2e1cf15ec]
-            libcrypto.so.1.0.0(DSA_new_method+0xe6) [0x7fe2e1d524d6]
-            libcrypto.so.1.0.0(DSA_generate_parameters+0x3a) [0x7fe2e1d5364a]
-            ^
-            |----- begin interesting
-
-            _cffi__x305d4698xb539baaa.so(+0x1f397) [0x7fe2df84d397]
-            cpython/2.7/python(PyCFunction_Call+0x8b) [0x56265a]
-            cpython/2.7/python() [0x4d5f52]
-            cpython/2.7/python(PyEval_EvalFrameEx+0x753b) [0x4d0e1e]
-            cpython/2.7/python() [0x4d6419]
-            ...
-
-            Notice the stack is upside down compared to a Python traceback.
-            Identify the start and end of interesting bits and stuff it into
-            the stack we report.
-            """
-            stacks = memdbg.heap[p]
-            # Eventually look at multiple stacks for the realloc() case.  For
-            # now just look at the original allocation location.
-            (size, python_stack, c_stack) = stacks[0]
-
-            stack = traceback.format_list(python_stack)[:-1]
-            saved = list(c_stack)
-
-            # Figure the first interesting frame will be after a the
-            # cffi-compiled module
-            while c_stack and '/__pycache__/_cffi__' not in c_stack[-1]:
-                c_stack.pop()
-
-            # Figure the last interesting frame will always be CRYPTO_malloc,
-            # since that's where we hooked in to things.
-            while (
-                c_stack and 'CRYPTO_malloc' not in c_stack[0] and
-                'CRYPTO_realloc' not in c_stack[0]
-            ):
-                c_stack.pop(0)
-
-            if c_stack:
-                c_stack.reverse()
-            else:
-                c_stack = saved[::-1]
-            stack.extend([frame + "\n" for frame in c_stack])
-
-            stack.insert(0, "Leaked (%s) at:\n")
-            return "".join(stack)
-
-        if leaks:
-            unique_leaks = {}
-            for p in leaks:
-                size = memdbg.heap[p][-1][0]
-                new_leak = format_leak(p)
-                if new_leak not in unique_leaks:
-                    unique_leaks[new_leak] = [(size, p)]
-                else:
-                    unique_leaks[new_leak].append((size, p))
-                memdbg.free(p)
-
-            for (stack, allocs) in unique_leaks.iteritems():
-                allocs_accum = []
-                for (size, pointer) in allocs:
-
-                    addr = int(ffi.cast('uintptr_t', pointer))
-                    allocs_accum.append("%d@0x%x" % (size, addr))
-                allocs_report = ", ".join(sorted(allocs_accum))
-
-                result.addError(
-                    self,
-                    (None, Exception(stack % (allocs_report,)), None))
-
-    _tmpdir = None
-
-    @property
-    def tmpdir(self):
-        """
-        On demand create a temporary directory.
-        """
-        if self._tmpdir is not None:
-            return self._tmpdir
-
-        self._tmpdir = mkdtemp(dir=".")
-        return self._tmpdir
-
-    def tearDown(self):
-        """
-        Clean up any files or directories created using
-        :py:meth:`TestCase.mktemp`.  Subclasses must invoke this method if they
-        override it or the cleanup will not occur.
-        """
-        if self._tmpdir is not None:
-            shutil.rmtree(self._tmpdir)
-
-        try:
-            exception_from_error_queue(Error)
-        except Error:
-            e = sys.exc_info()[1]
-            if e.args != ([],):
-                self.fail(
-                    "Left over errors in OpenSSL error queue: " + repr(e)
-                )
-
-    def assertIsInstance(self, instance, classOrTuple, message=None):
-        """
-        Fail if C{instance} is not an instance of the given class or of
-        one of the given classes.
-
-        @param instance: the object to test the type (first argument of the
-            C{isinstance} call).
-        @type instance: any.
-        @param classOrTuple: the class or classes to test against (second
-            argument of the C{isinstance} call).
-        @type classOrTuple: class, type, or tuple.
-
-        @param message: Custom text to include in the exception text if the
-            assertion fails.
-        """
-        assert isinstance(instance, classOrTuple)
-
-    def failUnlessIn(self, containee, container, msg=None):
-        """
-        Fail the test if :py:data:`containee` is not found in
-        :py:data:`container`.
-
-        :param containee: the value that should be in :py:class:`container`
-        :param container: a sequence type, or in the case of a mapping type,
-                          will follow semantics of 'if key in dict.keys()'
-        :param msg: if msg is None, then the failure message will be
-                    '%r not in %r' % (first, second)
-        """
-        assert containee in container
-    assertIn = failUnlessIn
-
-    def assertNotIn(self, containee, container, msg=None):
-        """
-        Fail the test if C{containee} is found in C{container}.
-
-        @param containee: the value that should not be in C{container}
-        @param container: a sequence type, or in the case of a mapping type,
-                          will follow semantics of 'if key in dict.keys()'
-        @param msg: if msg is None, then the failure message will be
-                    '%r in %r' % (first, second)
-        """
-        assert containee not in container
-    failIfIn = assertNotIn
-
-    def assertIs(self, first, second, msg=None):
-        """
-        Fail the test if :py:data:`first` is not :py:data:`second`.  This is an
-        obect-identity-equality test, not an object equality
-        (i.e. :py:func:`__eq__`) test.
-
-        :param msg: if msg is None, then the failure message will be
-        '%r is not %r' % (first, second)
-        """
-        assert first is second
-    assertIdentical = failUnlessIdentical = assertIs
-
-    def assertIsNot(self, first, second, msg=None):
-        """
-        Fail the test if :py:data:`first` is :py:data:`second`.  This is an
-        obect-identity-equality test, not an object equality
-        (i.e. :py:func:`__eq__`) test.
-
-        :param msg: if msg is None, then the failure message will be
-        '%r is %r' % (first, second)
-        """
-        assert first is not second
-    assertNotIdentical = failIfIdentical = assertIsNot
-
-    def failUnlessRaises(self, exception, f, *args, **kwargs):
-        """
-        Fail the test unless calling the function :py:data:`f` with the given
-        :py:data:`args` and :py:data:`kwargs` raises :py:data:`exception`. The
-        failure will report the traceback and call stack of the unexpected
-        exception.
-
-        :param exception: exception type that is to be expected
-        :param f: the function to call
-
-        :return: The raised exception instance, if it is of the given type.
-        :raise self.failureException: Raised if the function call does
-            not raise an exception or if it raises an exception of a
-            different type.
-        """
-        with pytest.raises(exception) as cm:
-            f(*args, **kwargs)
-        return cm.value
-    assertRaises = failUnlessRaises
-
-    def mktemp(self):
-        """
-        Return UTF-8-encoded bytes of a path to a tmp file.
-
-        The file will be cleaned up after the test run.
-        """
-        return mktemp(dir=self.tmpdir).encode("utf-8")
-
-    # Other stuff
-    def assertConsistentType(self, theType, name, *constructionArgs):
-        """
-        Perform various assertions about :py:data:`theType` to ensure that it
-        is a well-defined type.  This is useful for extension types, where it's
-        pretty easy to do something wacky.  If something about the type is
-        unusual, an exception will be raised.
-
-        :param theType: The type object about which to make assertions.
-        :param name: A string giving the name of the type.
-        :param constructionArgs: Positional arguments to use with
-            :py:data:`theType` to create an instance of it.
-        """
-        assert is_consistent_type(theType, name, *constructionArgs)
-
-
 def is_consistent_type(theType, name, *constructionArgs):
     """
     Perform various assertions about *theType* to ensure that it is a