<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def _device_node(self, device):
 """Create an empty menu node for the specified device."""

        label = device.ui_label
        dev_label = device.ui_device_label
        # determine available methods
        methods = [Action(method, device,
                          self._labels[method].format(label, dev_label),
                          partial(self._actions[method], device))
                   for method in self._get_device_methods(device)]
        # find the root device:
        root = device.parent_object_path
        # in this first step leave branches empty
        return device.object_path, Device(root, [], device, dev_label, methods)