def get_edge_ids_by_node_ids(self, node_a, node_b):
<EOL>if not self.adjacent(node_a, node_b):<EOL><INDENT>return []<EOL><DEDENT>node = self.get_node(node_a)<EOL>return [edge_id for edge_id in node['<STR_LIT>'] if self.get_edge(edge_id)['<STR_LIT>'][<NUM_LIT:1>] == node_b]<EOL>
Returns a list of edge ids connecting node_a to node_b.