def __init__(self, fd, data):
        """
        @param fd: A C{int} giving a file descriptor to send over the
            connection.

        @param data: A C{str} giving data to send over the connection, or
            L{None} if no data is to be sent.
        """
        self.fd = fd
        self.data = data

        @param fd: A C{int} giving a file descriptor to send over the
            connection.

        @param data: A C{str} giving data to send over the connection, or
            L{None} if no data is to be sent.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/internet/test/test_unix.py