lib/index.esm.js
function set(key, value) {
    return _collectionStrong.def(_validateCollection(this, MAP), key === 0 ? 0 : key, value);
  }
function set(key, value) {
    return _collectionStrong.def(_validateCollection(this, MAP), key === 0 ? 0 : key, value);
  }
23.1.3.9 Map.prototype.set(key, value)