1. 构造函数
2. RtcPeerConnectionIceEvent
3. 属性
4. bubbles
5. cancelable
6. candidate
7. composed
8. currentTarget
9. defaultPrevented
10. eventPhase
11. hashCode
12. isTrusted
13. matchingTarget
14. path
15. runtimeType
16. target
17. timeStamp
18. type
19. 方法
20. composedPath
21. noSuchMethod
22. preventDefault
23. stopImmediatePropagation
24. stopPropagation
25. toString
26. 运算符
27. 运算符 ==