nsIAtom*& aPrefix, nsString& aResult) const {
nsIAtom*& aPrefix, nsAWritableString& aResult) const {
  NS_IMETHOD GetAttribute(PRInt32 aNameSpaceID, nsIAtom* aName,                                      nsIAtom*& aPrefix, nsString& aResult) const {    return mInner.GetAttribute(aNameSpaceID, aName, aPrefix, aResult);  }