def test_no_call_signal_transferring_to_underlying_fileobj(self):
     underlying_stream = mock.Mock(io.RawIOBase)
     underlying_stream.tell.return_value = 0
     chunk = ReadFileChunk(underlying_stream, 3, 3)
     try:
         chunk.signal_transferring()
     except AttributeError:
         self.fail(
             'The stream should not have tried to call signal_transferring '
             'to the underlying stream.')
 def test_signal_transferring_to_underlying_fileobj(self):
     underlying_stream = mock.Mock()
     underlying_stream.tell.return_value = 0
     chunk = ReadFileChunk(underlying_stream, 3, 3)
     chunk.signal_transferring()
     self.assertTrue(underlying_stream.signal_transferring.called)