new_contents: from call_seq import CallSeq
  
  
  def test2():
      pass
  
  
  def test1():
      test2()
      return 1 + 1
  
  
  def test():
      test1()
      print 'call me'
      test1()
  
  
  if __name__ == '__main__':
      with CallSeq(name='output.json'):
          test()
subject: add demo file to show using `with` block to record how the program run.