code: def cardinality(self):
          
          data = clips.data.DataObject(self._env)
  
          lib.EnvDeftemplateSlotCardinality(
              self._env, self._tpl, self._name, data.byref)
  
          return tuple(data.value) if isinstance(data.value, list) else ()
docs: A tuple containing the cardinality for this Slot.
  
          The Python equivalent
          of the CLIPS deftemplate-slot-cardinality function.