code: @CheckReturnValue
      @SchedulerSupport(SchedulerSupport.NONE)
      public static Completable mergeArrayDelayError(CompletableSource... sources) {
          ObjectHelper.requireNonNull(sources, "sources is null");
          return RxJavaPlugins.onAssembly(new CompletableMergeDelayErrorArray(sources));
      }
docs: Returns a CompletableConsumable that subscribes to all Completables in the source array and delays
  any error emitted by either the sources observable or any of the inner Completables until all of
  them terminate in a way or another.
  <p>
  <img width="640" height="430" src="https://raw.github.com/wiki/ReactiveX/RxJava/images/rx-operators/Completable.mergeArrayDelayError.png" alt="">
  <dl>
  <dt><b>Scheduler:</b></dt>
  <dd>{@code mergeArrayDelayError} does not operate by default on a particular {@link Scheduler}.</dd>
  </dl>
  @param sources the array of Completables
  @return the new Completable instance
  @throws NullPointerException if sources is null