parameters: (self)
docstring: Customized operations for each model before update.
  
          To be extended.
docstring_summary: Customized operations for each model before update.
docstring_tokens: Customized operations for each model before update .
function: def before_update(self):
          """Customized operations for each model before update.
  
          To be extended.
  
          """
          pass
function_tokens: def before_update ( self ) : pass