This means that the node generated for the additive node will have a method named value. end这段代码的意思是通过additive节点生成的节点有一个叫做value的方法。
Specifies the named value to be deleted from the subkey. 指定要从子项中删除的指名的值。
Contains an array of string data values for the named value. 包含指名值的一个字符串数据值数组。
Specifies the key that contains the named value to be deleted. 指定项,它包含要删除的指名的值。
You can then treat each named value as an instance of that class, providing you with compile-time type safety that a named set of integers can't. 然后,可以将每个指定的值看作是那个类的一个实例,这为您提供了指定的整数集合所无法提供的编译时类型安全。