RxJS 1 array item into sequence of single items - operator

Question

Given such observable

Rx.Observable.of([1,2,3,4,5])

which emits a single item (that is an array), what is the operator

Answer 1

mergeAll:

Observable.of([4, 5, 6])
  .mergeAll()
  .subscribe(console.log);
// output:
// 4
// 5
// 6