def write(packet, addr=None):
        """
        Write packet to given address.

        @param addr: a tuple of (ip, port). For connected transports must
                     be the address the transport is connected to, or None.
                     In non-connected mode this is mandatory.

        @raise twisted.internet.error.MessageLengthError: C{packet} was too
        long.
        """

        Write packet to given address.

        @param addr: a tuple of (ip, port). For connected transports must
                     be the address the transport is connected to, or None.
                     In non-connected mode this is mandatory.

        @raise twisted.internet.error.MessageLengthError: C{packet} was too
        long.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/internet/interfaces.py