content: from .utils import DeprecationTestCase
  
  
  class BackwardsCompatibilityTests(DeprecationTestCase):
      def test_headers_class(self):
          with self.assertDeprecationWarning(
              "websockets.auth, an alias for websockets.legacy.auth, is deprecated; "
              "see https://websockets.readthedocs.io/en/stable/howto/upgrade.html "
              "for upgrade instructions",
          ):
              from websockets.auth import (
                  BasicAuthWebSocketServerProtocol,  # noqa: F401
                  basic_auth_protocol_factory,  # noqa: F401
              )
  