public boolean dispatchAsyncOnce(DispatchTask task, long delayMillis) {
		if (!task.isScheduled()) {
			dispatchAsync(task, delayMillis);
			return true;
		}
		return false;
	}
public boolean dispatchAsyncOnce ( DispatchTask task , long delayMillis ) { if ( ! task . isScheduled ( ) ) { dispatchAsync ( task , delayMillis ) ; return true ; } return false ; }
Add <code>{@link DispatchTask}</code> to the queue if it's not already on the queue (this
way you can ensure only one instance of the task is scheduled at a time). After the task is
executed you can schedule it again.

@return true if task was scheduled