def receiveUDP(fileno, host, port):
        """
        Return a socket which can be used to receive datagrams sent to the
        given address.

        @param fileno: A file descriptor representing a tunnel device which the
            datagram was either sent via or will be received via.
        @type fileno: L{int}

        @param host: The IPv4 address at which the datagram will be received.
        @type host: L{bytes}

        @param port: The UDP port number at which the datagram will be
            received.
        @type port: L{int}

        @return: A L{socket.socket} which can be used to receive the specified
            datagram.
        """

        Return a socket which can be used to receive datagrams sent to the
        given address.

        @param fileno: A file descriptor representing a tunnel device which the
            datagram was either sent via or will be received via.
        @type fileno: L{int}

        @param host: The IPv4 address at which the datagram will be received.
        @type host: L{bytes}

        @param port: The UDP port number at which the datagram will be
            received.
        @type port: L{int}

        @return: A L{socket.socket} which can be used to receive the specified
            datagram.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/pair/tuntap.py