def neighbors(self, node_id):
node = self.get_node(node_id)<EOL>return [self.get_edge(edge_id)['<STR_LIT>'][<NUM_LIT:1>] for edge_id in node['<STR_LIT>']]<EOL>
Find all the nodes where there is an edge from the specified node to that node.
        Returns a list of node ids.