docs: private Observable<Indexable> processFaultedTaskAsync(final TaskGroupEntry<TaskItem> faultedEntry,
                                                            final Throwable throwable,
                                                            final InvocationContext context) {
          markGroupAsCancelledIfTerminationStrategyIsIPTC();
          reportError(faultedEntry, throwable);
          if (isRootEntry(faultedEntry)) {
              if (shouldPropagateException(throwable)) {
                  return toErrorObservable(throwable);
              }
              return Observable.empty();
          } else if (shouldPropagateException(throwable)) {
              return Observable.concatDelayError(invokeReadyTasksAsync(context), toErrorObservable(throwable));
          } else {
              return invokeReadyTasksAsync(context);
          }
      }