Removes a port NIO binding.

        :param adapter_number: adapter number

        :returns: NIO instance

def adapter_remove_nio_binding(self, adapter_number):
        """
        Removes a port NIO binding.

        :param adapter_number: adapter number

        :returns: NIO instance
        """

        try:
            adapter = self._ethernet_adapters[adapter_number]
        except IndexError:
            raise QemuError('Adapter {adapter_number} does not exist on QEMU VM "{name}"'.format(name=self._name,
                                                                                                 adapter_number=adapter_number))

        if self.is_running():
            yield from self._ubridge_send("bridge delete {name}".format(name="QEMU-{}-{}".format(self._id, adapter_number)))

        nio = adapter.get_nio(0)
        if isinstance(nio, NIOUDP):
            self.manager.port_manager.release_udp_port(nio.lport, self._project)
        adapter.remove_nio(0)

        log.info('QEMU VM "{name}" [{id}]: {nio} removed from adapter {adapter_number}'.format(name=self._name,
                                                                                               id=self._id,
                                                                                               nio=nio,
                                                                                               adapter_number=adapter_number))
        return nio