nodes: 0, module; 1, function_definition; 2, function_name:sort_edge; 3, parameters; 4, block; 5, identifier:edges; 6, expression_statement; 7, return_statement; 8, comment:"""Sort iterable of edges first by left node indices then right.
  
          Args:
              edges(list[Edge]): List of edges to be sorted.
  
          Returns:
              list[Edge]: Sorted list by left and right node indices.
          """; 9, call; 10, identifier:sorted; 11, argument_list; 12, identifier:edges; 13, keyword_argument; 14, identifier:key; 15, lambda; 16, lambda_parameters; 17, tuple; 18, identifier:x; 19, attribute; 20, attribute; 21, identifier:x; 22, identifier:L; 23, identifier:x; 24, identifier:R
code: def sort_edge(edges):
          """Sort iterable of edges first by left node indices then right.
  
          Args:
              edges(list[Edge]): List of edges to be sorted.
  
          Returns:
              list[Edge]: Sorted list by left and right node indices.
          """
          return sorted(edges, key=lambda x: (x.L, x.R))