code: def test_missing_var():
      a = 3
      c = 5
      check("a+b+c", "b")
      check("z+b+c", "z")
  
file_path: tensor-sensor/testing/test_incr_eval.py
imports: from tsensor.ast import IncrEvalTrap
  from tsensor.parsing import PyExprParser
  import sys
  import numpy
  import torch
label_desc: Use image node_id 2 for calling a global function with example usage: test_missing_var() without return types