Use transient_internet() consistently in test_imaplib

Lib/test/test_imaplib.py

@@ -219,20 +219,23 @@ class RemoteIMAPTest(unittest.TestCase):
 
     def tearDown(self):
         if self.server is not None:
-            self.server.logout()
+            with transient_internet(self.host):
+                self.server.logout()
 
     def test_logincapa(self):
-        for cap in self.server.capabilities:
-            self.assertIsInstance(cap, str)
-        self.assertTrue('LOGINDISABLED' in self.server.capabilities)
-        self.assertTrue('AUTH=ANONYMOUS' in self.server.capabilities)
-        rs = self.server.login(self.username, self.password)
-        self.assertEqual(rs[0], 'OK')
+        with transient_internet(self.host):
+            for cap in self.server.capabilities:
+                self.assertIsInstance(cap, str)
+            self.assertTrue('LOGINDISABLED' in self.server.capabilities)
+            self.assertTrue('AUTH=ANONYMOUS' in self.server.capabilities)
+            rs = self.server.login(self.username, self.password)
+            self.assertEqual(rs[0], 'OK')
 
     def test_logout(self):
-        rs = self.server.logout()
-        self.server = None
-        self.assertEqual(rs[0], 'BYE')
+        with transient_internet(self.host):
+            rs = self.server.logout()
+            self.server = None
+            self.assertEqual(rs[0], 'BYE')
 
 
 @unittest.skipUnless(ssl, "SSL not available")
@@ -240,8 +243,9 @@ class RemoteIMAP_STARTTLSTest(RemoteIMAPTest):
 
     def setUp(self):
         super().setUp()
-        rs = self.server.starttls()
-        self.assertEqual(rs[0], 'OK')
+        with transient_internet(self.host):
+            rs = self.server.starttls()
+            self.assertEqual(rs[0], 'OK')
 
     def test_logincapa(self):
         for cap in self.server.capabilities: