#NEWLINE# @ classmethod #NEWLINE# def reserve( cls , context , tag , node_id ) : #NEWLINE# #INDENT# 'Get and reserve a node.\n\n        To prevent other ManagerServices from manipulating the given\n        Node while a Task is performed, mark it reserved by this host.\n\n        :param context: Security context.\n        :param tag: A string uniquely identifying the reservation holder.\n        :param node_id: A node id or uuid.\n        :raises: NodeNotFound if the node is not found.\n        :returns: a :class:`Node` object.\n\n        ' #NEWLINE# db_node = cls . dbapi . reserve_node ( tag , node_id ) #NEWLINE# node = Node . _from_db_object ( cls ( db_node ) , db_node ) #NEWLINE# return node