'Calling L{_InputStream.readlines} with an integer as an argument
returns a list of lines from the input stream with the argument serving
as an approximate bound on the total number of bytes to read.'

def test_readlinesSome(self):

    bytes = '123\n456\n789\n0'
    d = self._renderAndReturnReaderResult((lambda input: input.readlines(5)), bytes)
    def cbLines(lines):
        self.assertEqual(lines[:2], ['123\n', '456\n'])
    d.addCallback(cbLines)
    return d
