let suggestionStream = Observable.of(userStream, nilOnRefreshTapStream) .merge() .startWith(.None) suggestionStream.subscribeNext{ op in guard let u = op else { return self.clearCell(cell) } return self.setCell(cell, user: u ) }.addDisposableTo(cell.disposeBagCell) nilOnRefreshTapStream: --n-----------n--------n--------> userStream: -----u----u--------u-------u----> vvvvvvvvvvvv merge() vvvvvvvvvvvv suggestionStream: --s--s----s---s----s---s-------->