def test_readlineMoreThan(self):
        """
        Calling L{_InputStream.readline} with an integer which is greater than
        the number of bytes in the next line returns only the next line.
        """
        bytes = b"some lines\nof text"
        d = self._renderAndReturnReaderResult(
            lambda input: input.readline(20), bytes)
        d.addCallback(self.assertEqual, b"some lines\n")
        return d

        Calling L{_InputStream.readline} with an integer which is greater than
        the number of bytes in the next line returns only the next line.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/web/test/test_wsgi.py