アクセス変更子
The access modifiers of an item control the visibility (accessibility) of the item to other code. For example, you can call public methods from anywhere, whereas private methods can be called only from other methods within the same type.
属性
Attributes are used to provide additional information about elements within your program.
Constraints 段落
The Constraints paragraph allows specification of properties of the type parameters of a generic type or method, and therefore allows the use of methods or properties on data items whose type is specified as that parameter.