def get_port(self, adapter_number, port_number):
        """
        Return the port for this adapter_number and port_number
        or returns None if the port is not found
        """
        for port in self.ports:
            if port.adapter_number == adapter_number and port.port_number == port_number:
                return port
        return None
Return the port for this adapter_number and port_number
        or returns None if the port is not found