code: function getIENodeHash(node) {
    if (node && node.nodeType > 0) {
      switch (node.nodeType) {
        case 1: // Element
          return node.uniqueID;
        case 9: // Document
          return node.documentElement && node.documentElement.uniqueID;
      }
    }
  }
docs: IE has a `uniqueID` property on DOM nodes. We can construct the hash from it and avoid memory leaks from the IE cloneNode bug.