text: from unittest.mock import MagicMock, patch
  
  import pytest
  
  from httpcore._backends.asyncio import SocketStream
  
  
  class TestSocketStream:
      class TestIsReadable:
          @pytest.mark.asyncio
          async def test_returns_true_when_transport_has_no_socket(self):
              stream_reader = MagicMock()
              stream_reader._transport.get_extra_info.return_value = None
              sock_stream = SocketStream(stream_reader, MagicMock())
  
              assert sock_stream.is_readable()
  
          @pytest.mark.asyncio
          async def test_returns_true_when_socket_is_readable(self):
              stream_reader = MagicMock()
              stream_reader._transport.get_extra_info.return_value = MagicMock()
              sock_stream = SocketStream(stream_reader, MagicMock())
  
              with patch(
                  "httpcore._utils.is_socket_readable", MagicMock(return_value=True)
              ):
                  assert sock_stream.is_readable()
  