def test_readlinesNone(self):
        """
        Calling L{_InputStream.readlines} with L{None} as an argument returns
        all lines from the input.
        """
        bytes = b"one fish\ntwo fish\n"
        d = self._renderAndReturnReaderResult(
            lambda input: input.readlines(None), bytes)
        d.addCallback(self.assertEqual, [b"one fish\n", b"two fish\n"])
        return d

        Calling L{_InputStream.readlines} with L{None} as an argument returns
        all lines from the input.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/web/test/test_wsgi.py