node_modules/setprototypeof/index.js

module.exports = Object.setPrototypeOf || ({__proto__:[]} instanceof Array ? setProtoOf : mixinProperties);

function setProtoOf(obj, proto) {
	obj.__proto__ = proto;
	return obj;
}

function mixinProperties(obj, proto) {
	for (var prop in proto) {
		if (!obj.hasOwnProperty(prop)) {
			obj[prop] = proto[prop];
		}
	}
	return obj;
}