Method call

src/main/java/fieldbox/boxes/Box.java:237–241

(Function<G, T> f, Class<G> guard, Function<Box, Collection<Box>> direction)

	public <T> Optional<Box> where(Dict.Prop<T> find) {
		return whereHas(find, upwards()).findFirst();
	}

	@HiddenInAutocomplete
	public <G, T> Stream<T> call(Function<G, T> f, Class<G> guard, Function<Box, Collection<Box>> direction) {
		return breadthFirst(direction).filter(x -> guard.isInstance(x))
			.map(x -> f.apply((G) x));
	}