message: use enumerate instead of iterating with range and len
diff: @@ -795,7 +795,7 @@ def _find_children_hints_in_while_loop(function_def, nodes_mapping):
  # Make nodes inside function def inputs point to the real nodes.
  for node in function_def.node_def:
  - for i in range(len(node.input)):
  + for i, _ in enumerate(node.input):
  if node.input[i] in nodes_mapping:
  node.input[i] = nodes_mapping[node.input[i]]
  new_nodes.append(_copy.deepcopy(node))
  @@ -855,7 +855,7 @@ def _find_children_hints(call, graph_def):
  function_inputs = function_def.signature.input_arg
  assert len(inputs_outside_loop) == len(function_inputs)
  nodes_mapping = {}
  - for i in range(len(function_inputs)):
  + for i, _ in enumerate(function_inputs):
  nodes_mapping[function_inputs[i].name] = inputs_outside_loop[i]
  # TODO(b/123050804): Consider use grappler.
  (children_hints_in_loop,
  