### Question:
Transformers { static <F, E> Transformer<F, E> fromAction(final Action0 doEffect) { return fromAction(doEffect, null); } private  Transformers();   }### Answer:
@Test public void effectPerformerRunsActionWheneverEffectIsRequested() throws Exception { upstream.compose(Transformers.fromAction(action)).subscribe(); upstream.onNext("First Time"); assertThat(action.getRunCount(), is(1)); upstream.onNext("One more!"); assertThat(action.getRunCount(), is(2)); }
@Test public void effectPerformerRunsActionOnSchedulerWheneverEffectIsRequested() throws Exception { upstream.compose(Transformers.fromAction(action, scheduler)).subscribe(); upstream.onNext("First Time"); assertThat(action.getRunCount(), is(0)); scheduler.triggerActions(); assertThat(action.getRunCount(), is(1)); }