1. 构造函数
2. CanMakePaymentEvent
3. 属性
4. bubbles
5. cancelable
6. composed
7. currentTarget
8. defaultPrevented
9. eventPhase
10. hashCode
11. isTrusted
12. matchingTarget
13. methodData
14. modifiers
15. path
16. paymentRequestOrigin
17. runtimeType
18. target
19. timeStamp
20. topLevelOrigin
21. type
22. 方法
23. composedPath
24. noSuchMethod
25. preventDefault
26. respondWith
27. stopImmediatePropagation
28. stopPropagation
29. toString
30. waitUntil
31. 操作符
32. 操作符 ==