private static <T extends Event> void addHandler(@Nonnull Node node, @Nonnull EventHandler<T> handler,
	                                                 @Nonnull Function<Node, EventHandler<T>> handlerGetter,
	                                                 @Nonnull BiConsumer<Node, EventHandler<T>> handlerSetter) {
		EventHandler<T> oldHandler = handlerGetter.apply(node);
		handlerSetter.accept(node, new SplittingHandler<>(handler, oldHandler));
	}
@param node
		Node to remove from.
@param handler
		Handler to remove.
recaf-ui/src/main/java/software/coley/recaf/util/NodeEvents.java