bpo-40275: Move transient_internet from test.support to socket_helper (GH-19711)

diff --git a/Lib/test/test_urllib2net.py b/Lib/test/test_urllib2net.py
index b3a5e89..ba4c500 100644
--- a/Lib/test/test_urllib2net.py
+++ b/Lib/test/test_urllib2net.py
@@ -1,5 +1,6 @@
 import unittest
 from test import support
+from test.support import socket_helper
 from test.test_urllib2 import sanepathname2url
 
 import os
@@ -86,7 +87,7 @@
         # calling .close() on urllib2's response objects should close the
         # underlying socket
         url = support.TEST_HTTP_URL
-        with support.transient_internet(url):
+        with socket_helper.transient_internet(url):
             response = _urlopen_with_retry(url)
             sock = response.fp
             self.assertFalse(sock.closed)
@@ -159,7 +160,7 @@
 
     def test_urlwithfrag(self):
         urlwith_frag = "http://www.pythontest.net/index.html#frag"
-        with support.transient_internet(urlwith_frag):
+        with socket_helper.transient_internet(urlwith_frag):
             req = urllib.request.Request(urlwith_frag)
             res = urllib.request.urlopen(req)
             self.assertEqual(res.geturl(),
@@ -167,7 +168,7 @@
 
     def test_redirect_url_withfrag(self):
         redirect_url_with_frag = "http://www.pythontest.net/redir/with_frag/"
-        with support.transient_internet(redirect_url_with_frag):
+        with socket_helper.transient_internet(redirect_url_with_frag):
             req = urllib.request.Request(redirect_url_with_frag)
             res = urllib.request.urlopen(req)
             self.assertEqual(res.geturl(),
@@ -175,7 +176,7 @@
 
     def test_custom_headers(self):
         url = support.TEST_HTTP_URL
-        with support.transient_internet(url):
+        with socket_helper.transient_internet(url):
             opener = urllib.request.build_opener()
             request = urllib.request.Request(url)
             self.assertFalse(request.header_items())
@@ -193,7 +194,7 @@
 
         URL = 'http://www.imdb.com' # mangles Connection:close
 
-        with support.transient_internet(URL):
+        with socket_helper.transient_internet(URL):
             try:
                 with urllib.request.urlopen(URL) as res:
                     pass
@@ -223,7 +224,7 @@
                 else:
                     req = expected_err = None
 
-                with support.transient_internet(url):
+                with socket_helper.transient_internet(url):
                     try:
                         f = urlopen(url, req, support.INTERNET_TIMEOUT)
                     # urllib.error.URLError is a subclass of OSError
@@ -265,7 +266,7 @@
     def test_http_basic(self):
         self.assertIsNone(socket.getdefaulttimeout())
         url = support.TEST_HTTP_URL
-        with support.transient_internet(url, timeout=None):
+        with socket_helper.transient_internet(url, timeout=None):
             u = _urlopen_with_retry(url)
             self.addCleanup(u.close)
             self.assertIsNone(u.fp.raw._sock.gettimeout())
@@ -273,7 +274,7 @@
     def test_http_default_timeout(self):
         self.assertIsNone(socket.getdefaulttimeout())
         url = support.TEST_HTTP_URL
-        with support.transient_internet(url):
+        with socket_helper.transient_internet(url):
             socket.setdefaulttimeout(60)
             try:
                 u = _urlopen_with_retry(url)
@@ -285,7 +286,7 @@
     def test_http_no_timeout(self):
         self.assertIsNone(socket.getdefaulttimeout())
         url = support.TEST_HTTP_URL
-        with support.transient_internet(url):
+        with socket_helper.transient_internet(url):
             socket.setdefaulttimeout(60)
             try:
                 u = _urlopen_with_retry(url, timeout=None)
@@ -296,7 +297,7 @@
 
     def test_http_timeout(self):
         url = support.TEST_HTTP_URL
-        with support.transient_internet(url):
+        with socket_helper.transient_internet(url):
             u = _urlopen_with_retry(url, timeout=120)
             self.addCleanup(u.close)
             self.assertEqual(u.fp.raw._sock.gettimeout(), 120)
@@ -306,7 +307,7 @@
     @skip_ftp_test_on_travis
     def test_ftp_basic(self):
         self.assertIsNone(socket.getdefaulttimeout())
-        with support.transient_internet(self.FTP_HOST, timeout=None):
+        with socket_helper.transient_internet(self.FTP_HOST, timeout=None):
             u = _urlopen_with_retry(self.FTP_HOST)
             self.addCleanup(u.close)
             self.assertIsNone(u.fp.fp.raw._sock.gettimeout())
@@ -314,7 +315,7 @@
     @skip_ftp_test_on_travis
     def test_ftp_default_timeout(self):
         self.assertIsNone(socket.getdefaulttimeout())
-        with support.transient_internet(self.FTP_HOST):
+        with socket_helper.transient_internet(self.FTP_HOST):
             socket.setdefaulttimeout(60)
             try:
                 u = _urlopen_with_retry(self.FTP_HOST)
@@ -326,7 +327,7 @@
     @skip_ftp_test_on_travis
     def test_ftp_no_timeout(self):
         self.assertIsNone(socket.getdefaulttimeout())
-        with support.transient_internet(self.FTP_HOST):
+        with socket_helper.transient_internet(self.FTP_HOST):
             socket.setdefaulttimeout(60)
             try:
                 u = _urlopen_with_retry(self.FTP_HOST, timeout=None)
@@ -337,7 +338,7 @@
 
     @skip_ftp_test_on_travis
     def test_ftp_timeout(self):
-        with support.transient_internet(self.FTP_HOST):
+        with socket_helper.transient_internet(self.FTP_HOST):
             u = _urlopen_with_retry(self.FTP_HOST, timeout=60)
             self.addCleanup(u.close)
             self.assertEqual(u.fp.fp.raw._sock.gettimeout(), 60)