Method asMap_call

src/main/java/fieldbox/boxes/Box.java:859–863

(Object a, Object b)

		public boolean asMap_isProperty(String p) {
			return true;
		}

		@Override
		public Object asMap_call(Object a, Object b) {
			if (calling == null) throw new Error();
			return calling.apply(this, b);
		}