code: def leaf_itervars(stage):
      filtered = filter(
          lambda x: (x["index"] >= 0), stage["all_itervars"]
      )
      return sorted(filtered, key=lambda x: x["index"])
  
imports: import html
  import json
  import warnings
  from graphviz import Digraph
  from graphviz import Source
  import tvm
label_desc: Use image node_id 13 for calling a global function with example usage: leaf_itervars(stage) and returns: sorted