'Calling L{_InputStream.readline} a second time returns the line
following the line returned by the first call.'

def test_readlineTwice(self):

    bytes = 'first    line\nsecond    line\nlast    line'
    def readline(input):
        input.readline()
        return input.readline()
    d = self._renderAndReturnReaderResult(readline, bytes)
    d.addCallback(self.assertEqual, 'second    line\n')
    return d
