docstr: Collect the real children of all nodes in the graph
code: def find_real_children(cls, fx_graph):
      """Collect the real children of all nodes in the graph"""
  
      if cls.__verbosity > 0:
          print(
              "\n[find_real_children] Find the real children for each node according to the whole network graph built with Torch.FX"
          )
  
      reversible_fx_graph_keys = list(fx_graph.keys())
      for node_name in reversed(
          reversible_fx_graph_keys
      ):  # as the optimization, we need to find the real children from back to front, to use the already saved 'real_children'
          node_children = fx_graph.get(node_name).get("children")
  
          if cls.__verbosity > 2:
              print(
                  "[find_real_children] node_name: '{:}', children: {:}".format(
                      node_name, node_children
                  )
              )
  
          real_children = cls.find_node_real_children(
              fx_graph, node_name, set()
          )
  
          if cls.__verbosity > 1:
              print(
                  f"[find_real_children] {node_name} has {len(real_children)} real children: {real_children}"
              )
  
          fx_graph[node_name]["real_children"] = sorted(real_children)
  
      if cls.__save_permutation_graph:
          cls.save_graph_to_json(
              fx_graph,
              save_dumped_graph_path_with_name=os.path.join(
                  cls.__permutation_output_dir,
                  "./model_graph_find_real_children.json",
              ),
          )  # save the intermediate graph as JSON file for debugging
      return fx_graph
  
imports: import os
  import torch
  import json
  import string
  import time
  import numpy
  import sys
  import builtins
  import io
label_desc: Use image node_id 36 for calling the Permutation obj's underlying member method code with example usage: obj.find_real_children(cls, fx_graph) and returns: fx_graph