// `Map.prototype.upsert` method
// https://github.com/thumbsupep/proposal-upsert
module.exports = function upsert(key, updateFn /* , insertFn */) {
var map = anObject(this);
// `Map.prototype.upsert` method
// https://github.com/thumbsupep/proposal-upsert
module.exports = function upsert(key, updateFn /* , insertFn */) {
var map = anObject(this);