void Set(nsIAtom* aAttribute, const nsAString& aValue)
void Set(nsIAtom* aAttribute, const nsHTMLValue& aValue)
  void Set(nsIAtom* aAttribute, const nsAString& aValue)  {    mAttribute.Release();    mAttribute.mAtom = aAttribute;    mAttribute.Addref();    mValue.SetStringValue(aValue);  }