code: function (fn, context) {
              var self = this;
              util.each(self, function (n, i) {
                  n = new Node(n);
                  return fn.call(context || n, n, i, self);
              });
              return self;
          }
docs: Applies the given function to each Node in the Node.
  @param {Function} fn The function to apply. It receives 3 arguments:
  the current node instance, the node's index,
  and the Node instance
  @param [context] An optional context to
  apply the function with Default context is the current Node instance
  @return {KISSY.Node}