classBook:Object{//(…)varreadingSessions:[ReadingSession]{returnlinkingObjects(ReadingSession.self,forProperty:"book")}}classReadingSession:Object{//(…)varbook:Book?varaComputedProperty:Int{print(self)//PrintsReadingSession{book=Book{(…)}(…)}print(self.book)//Printsnil//(…)}}代码几乎说明了一切。如果我从我的计算属性