feature: vor und nachteile

praesentation/node_modules/define-lazy-prop/index.js

@@ -0,0 +1,18 @@
+export default function defineLazyProperty(object, propertyName, valueGetter) {
+	const define = value => Object.defineProperty(object, propertyName, {value, enumerable: true, writable: true});
+
+	Object.defineProperty(object, propertyName, {
+		configurable: true,
+		enumerable: true,
+		get() {
+			const result = valueGetter();
+			define(result);
+			return result;
+		},
+		set(value) {
+			define(value);
+		}
+	});
+
+	return object;
+}