delegate-properties
Deep-clone properties from one object to another and make them non-enumerable, or make existing properties on an object non-enumerable.
class-utils
Utils for working with JavaScript classes and prototype methods.
extend-shallow
Extend an object with the properties of additional objects. node.js/javascript util.
define-property
Define a non-enumerable property on an object. Uses Reflect.defineProperty when available, otherwise Object.defineProperty.
hasown
A robust, ES3 compatible, "has own property" predicate.