var each = function(collection, cb) {
      if (isArrayLike(collection)) {
        for (var i = 0; i < collection.length; i++) {
            cb.call(collection[i], i, collection[i]);
        }
      } else {
        for (var prop in collection) {
          cb.call(collection[prop], prop, collection[prop]);
        }
      }
}