code: function(fn) {
  			var arr = this.arr;
  
  			if (arr.length === undefined) {
  				// The wrapped array is a JSON object
  				for (var key in arr) {
  					this.arr[key] = fn.call(arr[key], arr[key], key, arr);
  				}
  			} else {
  				// The wrapped array is an array
  				for (var i = 0, l = this.arr.length; i < l; i++) {
  					this.arr[i] = fn.call(arr[i], arr[i], i, arr);
  				}
  			}
  
  			return this;
  		}
docs: Replaces each element in an array or JSON object with the result of the function that is called against each element.  fn - The function to call on each element el    - The array or object element index - The index or key of the array element  Returns nothing.