code: def get_neutralized_variable(variable):
      
      result = variable.clone()
      result.is_neutralized = True
      result.label = '[Neutralized]' if variable.label is None else '[Neutralized] {}'.format(variable.label),
  
      return result
docs: Return a new neutralized variable (to be used by reforms).
          A neutralized variable always returns its default value, and does not cache anything.