Send message to recipient if the transport is running.

def maybe_send(self, recipient: Address, message: Message):
        """ Send message to recipient if the transport is running. """

        if not is_binary_address(recipient):
            raise InvalidAddress('Invalid address {}'.format(pex(recipient)))

        messagedata = message.encode()
        host_port = self.get_host_port(recipient)

        self.maybe_sendraw(host_port, messagedata)