old_contents: """Function for Debuging."""
  import inspect
  
  
  def pv(name):
      # type: (str) -> str
      """Analysis an expresion 'expresion : evaulation'.
  
      Used to help debuging values.
      """
      frame = inspect.currentframe().f_back
      val = eval(name, frame.f_globals, frame.f_locals)
      return '{0}: {1}'.format(name, val)
  
new_contents: """Function for Debuging."""
  import inspect
  
  
  def pv(name):
      # type: (str) -> str
      """Analysis an expresion 'expresion : evaulation'.
  
      Used to help debuging values.
      """
      if "__" in name:
          raise ValueError("Double underscores not allowed for saftey reasons.")
      frame = inspect.currentframe().f_back
      val = eval(name, frame.f_globals, frame.f_locals)
      return '{0}: {1}'.format(name, val)
  
subject: Disable dunder evaluation in debuging tool.