code: def get_system(self, twig=None, **kwargs):
          
          if twig is not None:
              kwargs['twig'] = twig
          kwargs['context'] = 'system'
          return self.filter(**kwargs)
docs: Filter in the 'system' context
  
          :parameter str twig: twig to use for filtering
          :parameter **kwargs: any other tags to do the filter
              (except twig or context)
  
          :return: :class:`phoebe.parameters.parameters.Parameter` or
              :class:`phoebe.parameters.parameters.ParameterSet`