Send an ISOTP frame and block until the message is sent or an error
        happens.

def send(self, p):
        """Send an ISOTP frame and block until the message is sent or an error
        happens."""
        with self.send_mutex:
            self.begin_send(p)

            # Wait until the tx callback is called
            self.tx_done.wait()
            if self.tx_exception is not None:
                raise Scapy_Exception(self.tx_exception)
            return