def listenUNIX(address, factory, backlog=50, mode=0o666, wantPID=0):
        """
        Listen on a UNIX socket.

        @param address: a path to a unix socket on the filesystem.

        @param factory: a L{twisted.internet.protocol.Factory} instance.

        @param backlog: number of connections to allow in backlog.

        @param mode: The mode (B{not} umask) to set on the unix socket.  See
            platform specific documentation for information about how this
            might affect connection attempts.
        @type mode: C{int}

        @param wantPID: if True, create a pidfile for the socket.  If C{address}
            is a Linux abstract namespace path, this must be C{False}.

        @return: An object which provides L{IListeningPort}.
        """

        Listen on a UNIX socket.

        @param address: a path to a unix socket on the filesystem.

        @param factory: a L{twisted.internet.protocol.Factory} instance.

        @param backlog: number of connections to allow in backlog.

        @param mode: The mode (B{not} umask) to set on the unix socket.  See
            platform specific documentation for information about how this
            might affect connection attempts.
        @type mode: C{int}

        @param wantPID: if True, create a pidfile for the socket.  If C{address}
            is a Linux abstract namespace path, this must be C{False}.

        @return: An object which provides L{IListeningPort}.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/internet/interfaces.py