An overview of each packet and all types of packets, a brief descr iption, in addition to the paint included in the category of the inheritance hierarchy diagram.

• 包概述对每个包及其所有类进行了简要描述，另外还画出了包中的类的继承层次结构示意图。每个类描述都独自构成一个小节，包含了类层次结构示意图、类描述、类示例、成员概述.