example for https://stackoverflow.com/questions/54829140/pausable-buffer-with-rxjs

index.js

const { rxObserver } = require('api/v0.3');
const { Observable } = require('rxjs/Rx');
const { timer } = require('rxjs');

const autoSave$ = Observable
  .timer(0, 17)
  .map(v => v%2 == 1)
  .takeUntil(timer(100))
  .share();

const changes$ =Observable
  .timer(5, 10)
  .takeUntil(timer(100))
  .share();

const output$ = 
  autoSave$
    .mergeMap(value =>
      value
      ? changes$
        .takeUntil(autoSave$)
      : changes$
        .bufferWhen(()=> autoSave$.filter(v=>v))
        .take(1)
        .flatMap(x=>x)
    );


changes$.subscribe(rxObserver('Changes'));
autoSave$.subscribe(rxObserver('Auto save toggle'));
output$.subscribe(rxObserver('Output'));