我不太明白“returnsObjectsAsFaults”的用法。文档说:ABooleanvaluethatindicateswhethertheobjectsresultingfromafetchusingthereceiverarefaults.YESiftheobjectsresultingfromafetchusingthereceiverarefaults,otherwiseNO.ThedefaultvalueisYES.Thissettingisnotusediftheresulttype(seeresultType)isNSManagedObjectIDResultTyp