code: public static <T> StoppableObservable<T> runAsync(Scheduler scheduler, 
              final Action2<? super Observer<? super T>, ? super Subscription> action) {
          return runAsync(scheduler, PublishSubject.<T>create(), action);
      }
docs: Runs the provided action on the given scheduler and allows propagation of multiple events to the
  observers of the returned StoppableObservable. The action is immediately executed and unobserved values
  will be lost.
  
  @param <T> the output value type
  @param scheduler the Scheduler where the action is executed
  @param action the action to execute, receives an Observer where the events can be pumped and a
  Subscription which lets it check for cancellation condition
  @return an Observable that provides a Subscription interface to cancel the action
  @see <a href="https://github.com/ReactiveX/RxJava/wiki/Async-Operators#wiki-runasync">RxJava Wiki: runAsync()</a>