code: function(fn, testSelf) {
          return Y.one(Y_DOM.ancestor(this._node, _wrapFn(fn), testSelf));
      }
docs: Returns the nearest ancestor that passes the test applied by supplied boolean method.
  @method ancestor
  @param {String | Function} fn A selector string or boolean method for testing elements.
  @param {Boolean} testSelf optional Whether or not to include the element in the scan
  If a function is used, it receives the current node being tested as the only argument.
  @return {Node} The matching Node instance or null if not found