1. Dart
2. dart:html
3. PaymentInstruments
4. has method

PaymentInstruments class

1. Properties
2. hashCode
3. runtimeType
4. Methods
5. clear
6. delete
7. get
8. has
9. keys
10. set
11. noSuchMethod
12. toString
13. Operators
14. operator ==

Future has(String instrumentKey) =>
    promiseToFuture(JS("", "#.has(#)", this, instrumentKey));