Consider `copyOwnFrom`

[dotproto]

Dr. Axel has a copyOwnFrom helper function that may be useful on http://www.2ality.com/2011/12/subtyping-builtins.html.

function copyOwnFrom(target, source) {
    Object.getOwnPropertyNames(source).forEach(function(propName) {
        Object.defineProperty(target, propName, Object.getOwnPropertyDescriptor(source, propName));
    });
    return target;
};