code: public static <P extends ICallbackPredicate> CallbackOption<P> of(Priority priority)
  		{
  			return new CallbackOption<>(null, priority);
  		}
docs: Constructs a {@link ICallback.CallbackOption} with predicate {@link ICallback.ICallbackPredicate#alwaysTrue()} and the specified
  {@link Priority}.
  
  @param <P> the generic type
  @param priority the priority
  @return the callback option