code: def galprop_ringkey(self, **kwargs):
          
          kwargs_copy = self.base_dict.copy()
          kwargs_copy.update(**kwargs)
          self._replace_none(kwargs_copy)        
          try:
              return NameFactory.galprop_ringkey_format.format(**kwargs_copy)
          except KeyError:
              return None
docs: return the sourcekey for galprop input maps : specifies the component and ring