chore: blacken (#375)

diff --git a/tests/test__default.py b/tests/test__default.py
index d143479..2c86f3f 100644
--- a/tests/test__default.py
+++ b/tests/test__default.py
@@ -27,94 +27,96 @@
 import google.oauth2.credentials
 
 
-DATA_DIR = os.path.join(os.path.dirname(__file__), 'data')
-AUTHORIZED_USER_FILE = os.path.join(DATA_DIR, 'authorized_user.json')
+DATA_DIR = os.path.join(os.path.dirname(__file__), "data")
+AUTHORIZED_USER_FILE = os.path.join(DATA_DIR, "authorized_user.json")
 
 with open(AUTHORIZED_USER_FILE) as fh:
     AUTHORIZED_USER_FILE_DATA = json.load(fh)
 
 AUTHORIZED_USER_CLOUD_SDK_FILE = os.path.join(
-    DATA_DIR, 'authorized_user_cloud_sdk.json')
+    DATA_DIR, "authorized_user_cloud_sdk.json"
+)
 
-SERVICE_ACCOUNT_FILE = os.path.join(DATA_DIR, 'service_account.json')
+SERVICE_ACCOUNT_FILE = os.path.join(DATA_DIR, "service_account.json")
 
 with open(SERVICE_ACCOUNT_FILE) as fh:
     SERVICE_ACCOUNT_FILE_DATA = json.load(fh)
 
 LOAD_FILE_PATCH = mock.patch(
-    'google.auth._default._load_credentials_from_file', return_value=(
-        mock.sentinel.credentials, mock.sentinel.project_id), autospec=True)
+    "google.auth._default._load_credentials_from_file",
+    return_value=(mock.sentinel.credentials, mock.sentinel.project_id),
+    autospec=True,
+)
 
 
 def test__load_credentials_from_missing_file():
     with pytest.raises(exceptions.DefaultCredentialsError) as excinfo:
-        _default._load_credentials_from_file('')
+        _default._load_credentials_from_file("")
 
-    assert excinfo.match(r'not found')
+    assert excinfo.match(r"not found")
 
 
 def test__load_credentials_from_file_invalid_json(tmpdir):
-    jsonfile = tmpdir.join('invalid.json')
-    jsonfile.write('{')
+    jsonfile = tmpdir.join("invalid.json")
+    jsonfile.write("{")
 
     with pytest.raises(exceptions.DefaultCredentialsError) as excinfo:
         _default._load_credentials_from_file(str(jsonfile))
 
-    assert excinfo.match(r'not a valid json file')
+    assert excinfo.match(r"not a valid json file")
 
 
 def test__load_credentials_from_file_invalid_type(tmpdir):
-    jsonfile = tmpdir.join('invalid.json')
-    jsonfile.write(json.dumps({'type': 'not-a-real-type'}))
+    jsonfile = tmpdir.join("invalid.json")
+    jsonfile.write(json.dumps({"type": "not-a-real-type"}))
 
     with pytest.raises(exceptions.DefaultCredentialsError) as excinfo:
         _default._load_credentials_from_file(str(jsonfile))
 
-    assert excinfo.match(r'does not have a valid type')
+    assert excinfo.match(r"does not have a valid type")
 
 
 def test__load_credentials_from_file_authorized_user():
-    credentials, project_id = _default._load_credentials_from_file(
-        AUTHORIZED_USER_FILE)
+    credentials, project_id = _default._load_credentials_from_file(AUTHORIZED_USER_FILE)
     assert isinstance(credentials, google.oauth2.credentials.Credentials)
     assert project_id is None
 
 
 def test__load_credentials_from_file_authorized_user_bad_format(tmpdir):
-    filename = tmpdir.join('authorized_user_bad.json')
-    filename.write(json.dumps({'type': 'authorized_user'}))
+    filename = tmpdir.join("authorized_user_bad.json")
+    filename.write(json.dumps({"type": "authorized_user"}))
 
     with pytest.raises(exceptions.DefaultCredentialsError) as excinfo:
         _default._load_credentials_from_file(str(filename))
 
-    assert excinfo.match(r'Failed to load authorized user')
-    assert excinfo.match(r'missing fields')
+    assert excinfo.match(r"Failed to load authorized user")
+    assert excinfo.match(r"missing fields")
 
 
 def test__load_credentials_from_file_authorized_user_cloud_sdk():
-    with pytest.warns(UserWarning, match='Cloud SDK'):
+    with pytest.warns(UserWarning, match="Cloud SDK"):
         credentials, project_id = _default._load_credentials_from_file(
-            AUTHORIZED_USER_CLOUD_SDK_FILE)
+            AUTHORIZED_USER_CLOUD_SDK_FILE
+        )
     assert isinstance(credentials, google.oauth2.credentials.Credentials)
     assert project_id is None
 
 
 def test__load_credentials_from_file_service_account():
-    credentials, project_id = _default._load_credentials_from_file(
-        SERVICE_ACCOUNT_FILE)
+    credentials, project_id = _default._load_credentials_from_file(SERVICE_ACCOUNT_FILE)
     assert isinstance(credentials, service_account.Credentials)
-    assert project_id == SERVICE_ACCOUNT_FILE_DATA['project_id']
+    assert project_id == SERVICE_ACCOUNT_FILE_DATA["project_id"]
 
 
 def test__load_credentials_from_file_service_account_bad_format(tmpdir):
-    filename = tmpdir.join('serivce_account_bad.json')
-    filename.write(json.dumps({'type': 'service_account'}))
+    filename = tmpdir.join("serivce_account_bad.json")
+    filename.write(json.dumps({"type": "service_account"}))
 
     with pytest.raises(exceptions.DefaultCredentialsError) as excinfo:
         _default._load_credentials_from_file(str(filename))
 
-    assert excinfo.match(r'Failed to load service account')
-    assert excinfo.match(r'missing fields')
+    assert excinfo.match(r"Failed to load service account")
+    assert excinfo.match(r"missing fields")
 
 
 @mock.patch.dict(os.environ, {}, clear=True)
@@ -124,19 +126,19 @@
 
 @LOAD_FILE_PATCH
 def test__get_explicit_environ_credentials(load, monkeypatch):
-    monkeypatch.setenv(environment_vars.CREDENTIALS, 'filename')
+    monkeypatch.setenv(environment_vars.CREDENTIALS, "filename")
 
     credentials, project_id = _default._get_explicit_environ_credentials()
 
     assert credentials is mock.sentinel.credentials
     assert project_id is mock.sentinel.project_id
-    load.assert_called_with('filename')
+    load.assert_called_with("filename")
 
 
 @LOAD_FILE_PATCH
 def test__get_explicit_environ_credentials_no_project_id(load, monkeypatch):
     load.return_value = mock.sentinel.credentials, None
-    monkeypatch.setenv(environment_vars.CREDENTIALS, 'filename')
+    monkeypatch.setenv(environment_vars.CREDENTIALS, "filename")
 
     credentials, project_id = _default._get_explicit_environ_credentials()
 
@@ -146,8 +148,8 @@
 
 @LOAD_FILE_PATCH
 @mock.patch(
-    'google.auth._cloud_sdk.get_application_default_credentials_path',
-    autospec=True)
+    "google.auth._cloud_sdk.get_application_default_credentials_path", autospec=True
+)
 def test__get_gcloud_sdk_credentials(get_adc_path, load):
     get_adc_path.return_value = SERVICE_ACCOUNT_FILE
 
@@ -159,10 +161,10 @@
 
 
 @mock.patch(
-    'google.auth._cloud_sdk.get_application_default_credentials_path',
-    autospec=True)
+    "google.auth._cloud_sdk.get_application_default_credentials_path", autospec=True
+)
 def test__get_gcloud_sdk_credentials_non_existent(get_adc_path, tmpdir):
-    non_existent = tmpdir.join('non-existent')
+    non_existent = tmpdir.join("non-existent")
     get_adc_path.return_value = str(non_existent)
 
     credentials, project_id = _default._get_gcloud_sdk_credentials()
@@ -172,12 +174,13 @@
 
 
 @mock.patch(
-    'google.auth._cloud_sdk.get_project_id',
-    return_value=mock.sentinel.project_id, autospec=True)
-@mock.patch('os.path.isfile', return_value=True, autospec=True)
+    "google.auth._cloud_sdk.get_project_id",
+    return_value=mock.sentinel.project_id,
+    autospec=True,
+)
+@mock.patch("os.path.isfile", return_value=True, autospec=True)
 @LOAD_FILE_PATCH
-def test__get_gcloud_sdk_credentials_project_id(
-        load, unused_isfile, get_project_id):
+def test__get_gcloud_sdk_credentials_project_id(load, unused_isfile, get_project_id):
     # Don't return a project ID from load file, make the function check
     # the Cloud SDK project.
     load.return_value = mock.sentinel.credentials, None
@@ -189,13 +192,10 @@
     assert get_project_id.called
 
 
-@mock.patch(
-    'google.auth._cloud_sdk.get_project_id',
-    return_value=None, autospec=True)
-@mock.patch('os.path.isfile', return_value=True)
+@mock.patch("google.auth._cloud_sdk.get_project_id", return_value=None, autospec=True)
+@mock.patch("os.path.isfile", return_value=True)
 @LOAD_FILE_PATCH
-def test__get_gcloud_sdk_credentials_no_project_id(
-        load, unused_isfile, get_project_id):
+def test__get_gcloud_sdk_credentials_no_project_id(load, unused_isfile, get_project_id):
     # Don't return a project ID from load file, make the function check
     # the Cloud SDK project.
     load.return_value = mock.sentinel.credentials, None
@@ -212,6 +212,7 @@
     See https://cloud.google.com/appengine/docs/standard/python/refdocs\
     /google.appengine.api.app_identity.app_identity
     """
+
     def get_application_id(self):
         raise NotImplementedError()
 
@@ -219,10 +220,8 @@
 @pytest.fixture
 def app_identity(monkeypatch):
     """Mocks the app_identity module for google.auth.app_engine."""
-    app_identity_module = mock.create_autospec(
-        _AppIdentityModule, instance=True)
-    monkeypatch.setattr(
-        app_engine, 'app_identity', app_identity_module)
+    app_identity_module = mock.create_autospec(_AppIdentityModule, instance=True)
+    monkeypatch.setattr(app_engine, "app_identity", app_identity_module)
     yield app_identity_module
 
 
@@ -237,8 +236,9 @@
 
 def test__get_gae_credentials_no_app_engine():
     import sys
-    with mock.patch.dict('sys.modules'):
-        sys.modules['google.auth.app_engine'] = None
+
+    with mock.patch.dict("sys.modules"):
+        sys.modules["google.auth.app_engine"] = None
         credentials, project_id = _default._get_gae_credentials()
         assert credentials is None
         assert project_id is None
@@ -249,21 +249,23 @@
 
 
 @mock.patch(
-    'google.auth.compute_engine._metadata.ping', return_value=True,
-    autospec=True)
+    "google.auth.compute_engine._metadata.ping", return_value=True, autospec=True
+)
 @mock.patch(
-    'google.auth.compute_engine._metadata.get_project_id',
-    return_value='example-project', autospec=True)
+    "google.auth.compute_engine._metadata.get_project_id",
+    return_value="example-project",
+    autospec=True,
+)
 def test__get_gce_credentials(unused_get, unused_ping):
     credentials, project_id = _default._get_gce_credentials()
 
     assert isinstance(credentials, compute_engine.Credentials)
-    assert project_id == 'example-project'
+    assert project_id == "example-project"
 
 
 @mock.patch(
-    'google.auth.compute_engine._metadata.ping', return_value=False,
-    autospec=True)
+    "google.auth.compute_engine._metadata.ping", return_value=False, autospec=True
+)
 def test__get_gce_credentials_no_ping(unused_ping):
     credentials, project_id = _default._get_gce_credentials()
 
@@ -272,11 +274,13 @@
 
 
 @mock.patch(
-    'google.auth.compute_engine._metadata.ping', return_value=True,
-    autospec=True)
+    "google.auth.compute_engine._metadata.ping", return_value=True, autospec=True
+)
 @mock.patch(
-    'google.auth.compute_engine._metadata.get_project_id',
-    side_effect=exceptions.TransportError(), autospec=True)
+    "google.auth.compute_engine._metadata.get_project_id",
+    side_effect=exceptions.TransportError(),
+    autospec=True,
+)
 def test__get_gce_credentials_no_project_id(unused_get, unused_ping):
     credentials, project_id = _default._get_gce_credentials()
 
@@ -286,110 +290,125 @@
 
 def test__get_gce_credentials_no_compute_engine():
     import sys
-    with mock.patch.dict('sys.modules'):
-        sys.modules['google.auth.compute_engine'] = None
+
+    with mock.patch.dict("sys.modules"):
+        sys.modules["google.auth.compute_engine"] = None
         credentials, project_id = _default._get_gce_credentials()
         assert credentials is None
         assert project_id is None
 
 
 @mock.patch(
-    'google.auth.compute_engine._metadata.ping', return_value=False,
-    autospec=True)
+    "google.auth.compute_engine._metadata.ping", return_value=False, autospec=True
+)
 def test__get_gce_credentials_explicit_request(ping):
     _default._get_gce_credentials(mock.sentinel.request)
     ping.assert_called_with(request=mock.sentinel.request)
 
 
 @mock.patch(
-    'google.auth._default._get_explicit_environ_credentials',
+    "google.auth._default._get_explicit_environ_credentials",
     return_value=(mock.sentinel.credentials, mock.sentinel.project_id),
-    autospec=True)
+    autospec=True,
+)
 def test_default_early_out(unused_get):
-    assert _default.default() == (
-        mock.sentinel.credentials, mock.sentinel.project_id)
+    assert _default.default() == (mock.sentinel.credentials, mock.sentinel.project_id)
 
 
 @mock.patch(
-    'google.auth._default._get_explicit_environ_credentials',
+    "google.auth._default._get_explicit_environ_credentials",
     return_value=(mock.sentinel.credentials, mock.sentinel.project_id),
-    autospec=True)
+    autospec=True,
+)
 def test_default_explict_project_id(unused_get, monkeypatch):
-    monkeypatch.setenv(environment_vars.PROJECT, 'explicit-env')
-    assert _default.default() == (
-        mock.sentinel.credentials, 'explicit-env')
+    monkeypatch.setenv(environment_vars.PROJECT, "explicit-env")
+    assert _default.default() == (mock.sentinel.credentials, "explicit-env")
 
 
 @mock.patch(
-    'google.auth._default._get_explicit_environ_credentials',
+    "google.auth._default._get_explicit_environ_credentials",
     return_value=(mock.sentinel.credentials, mock.sentinel.project_id),
-    autospec=True)
+    autospec=True,
+)
 def test_default_explict_legacy_project_id(unused_get, monkeypatch):
-    monkeypatch.setenv(environment_vars.LEGACY_PROJECT, 'explicit-env')
-    assert _default.default() == (
-        mock.sentinel.credentials, 'explicit-env')
+    monkeypatch.setenv(environment_vars.LEGACY_PROJECT, "explicit-env")
+    assert _default.default() == (mock.sentinel.credentials, "explicit-env")
 
 
+@mock.patch("logging.Logger.warning", autospec=True)
 @mock.patch(
-    'logging.Logger.warning',
-    autospec=True)
+    "google.auth._default._get_explicit_environ_credentials",
+    return_value=(mock.sentinel.credentials, None),
+    autospec=True,
+)
 @mock.patch(
-    'google.auth._default._get_explicit_environ_credentials',
-    return_value=(mock.sentinel.credentials, None), autospec=True)
+    "google.auth._default._get_gcloud_sdk_credentials",
+    return_value=(mock.sentinel.credentials, None),
+    autospec=True,
+)
 @mock.patch(
-    'google.auth._default._get_gcloud_sdk_credentials',
-    return_value=(mock.sentinel.credentials, None), autospec=True)
+    "google.auth._default._get_gae_credentials",
+    return_value=(mock.sentinel.credentials, None),
+    autospec=True,
+)
 @mock.patch(
-    'google.auth._default._get_gae_credentials',
-    return_value=(mock.sentinel.credentials, None), autospec=True)
-@mock.patch(
-    'google.auth._default._get_gce_credentials',
-    return_value=(mock.sentinel.credentials, None), autospec=True)
+    "google.auth._default._get_gce_credentials",
+    return_value=(mock.sentinel.credentials, None),
+    autospec=True,
+)
 def test_default_without_project_id(
-        unused_gce, unused_gae, unused_sdk, unused_explicit, logger_warning):
-    assert _default.default() == (
-        mock.sentinel.credentials, None)
+    unused_gce, unused_gae, unused_sdk, unused_explicit, logger_warning
+):
+    assert _default.default() == (mock.sentinel.credentials, None)
     logger_warning.assert_called_with(mock.ANY, mock.ANY, mock.ANY)
 
 
 @mock.patch(
-    'google.auth._default._get_explicit_environ_credentials',
-    return_value=(None, None), autospec=True)
+    "google.auth._default._get_explicit_environ_credentials",
+    return_value=(None, None),
+    autospec=True,
+)
 @mock.patch(
-    'google.auth._default._get_gcloud_sdk_credentials',
-    return_value=(None, None), autospec=True)
+    "google.auth._default._get_gcloud_sdk_credentials",
+    return_value=(None, None),
+    autospec=True,
+)
 @mock.patch(
-    'google.auth._default._get_gae_credentials',
-    return_value=(None, None), autospec=True)
+    "google.auth._default._get_gae_credentials",
+    return_value=(None, None),
+    autospec=True,
+)
 @mock.patch(
-    'google.auth._default._get_gce_credentials',
-    return_value=(None, None), autospec=True)
+    "google.auth._default._get_gce_credentials",
+    return_value=(None, None),
+    autospec=True,
+)
 def test_default_fail(unused_gce, unused_gae, unused_sdk, unused_explicit):
     with pytest.raises(exceptions.DefaultCredentialsError):
         assert _default.default()
 
 
 @mock.patch(
-    'google.auth._default._get_explicit_environ_credentials',
+    "google.auth._default._get_explicit_environ_credentials",
     return_value=(mock.sentinel.credentials, mock.sentinel.project_id),
-    autospec=True)
-@mock.patch(
-    'google.auth.credentials.with_scopes_if_required', autospec=True)
+    autospec=True,
+)
+@mock.patch("google.auth.credentials.with_scopes_if_required", autospec=True)
 def test_default_scoped(with_scopes, unused_get):
-    scopes = ['one', 'two']
+    scopes = ["one", "two"]
 
     credentials, project_id = _default.default(scopes=scopes)
 
     assert credentials == with_scopes.return_value
     assert project_id == mock.sentinel.project_id
-    with_scopes.assert_called_once_with(
-        mock.sentinel.credentials, scopes)
+    with_scopes.assert_called_once_with(mock.sentinel.credentials, scopes)
 
 
 @mock.patch(
-    'google.auth._default._get_explicit_environ_credentials',
+    "google.auth._default._get_explicit_environ_credentials",
     return_value=(mock.sentinel.credentials, mock.sentinel.project_id),
-    autospec=True)
+    autospec=True,
+)
 def test_default_no_app_engine_compute_engine_module(unused_get):
     """
     google.auth.compute_engine and google.auth.app_engine are both optional
@@ -397,8 +416,11 @@
     that default fails gracefully if these modules are absent
     """
     import sys
-    with mock.patch.dict('sys.modules'):
-        sys.modules['google.auth.compute_engine'] = None
-        sys.modules['google.auth.app_engine'] = None
+
+    with mock.patch.dict("sys.modules"):
+        sys.modules["google.auth.compute_engine"] = None
+        sys.modules["google.auth.app_engine"] = None
         assert _default.default() == (
-            mock.sentinel.credentials, mock.sentinel.project_id)
+            mock.sentinel.credentials,
+            mock.sentinel.project_id,
+        )