object.forEach [JS 1.8]

Object.prototype.forEach = function(fun /*, thisp*/) {
  // if this gets called on an array, use appropriate forEach
  if ( Object.prototype.toString.call(this) == "[object Array]" ) return Array.prototype.forEach.apply(this, Array.prototype.slice.call(arguments));
  if ( typeof fun != "function" ) throw new TypeError();
  let it = Iterator(this), thisp = arguments[1];
  try {
    while (true) {
      fun.apply(thisp, it.next());
    }
  } catch (err if err instanceof StopIteration) {}
}