1. Dart
2. dart:html
3. NetworkInformation
4. rtt property

NetworkInformation class

1. Properties
2. downlink
3. downlinkMax
4. effectiveType
5. onChange
6. rtt
7. type
8. hashCode
9. on
10. runtimeType
11. Methods
12. addEventListener
13. dispatchEvent
14. noSuchMethod
15. removeEventListener
16. toString
17. Operators
18. operator ==
19. Constants
20. changeEvent

int get rtt native;