debounce method
Creates an Observable that will only emit items from the source sequence if a particular time span has passed without the source sequence emitting another item.
The Debounce operator filters out items emitted by the source Observable that are rapidly followed by another emitted item.
Example
new Observable.range(1, 100)
.debounce(new Duration(seconds: 1))
.listen(print); // prints 100
Implementation
Observable<T> debounce(Duration duration) =>
transform(new DebounceStreamTransformer<T>(duration));