void Set(nsIAtom* aAttribute, const nsHTMLValue& aValue)
void Set(nsIAtom* aAttribute, const nsAReadableString& aValue)
  void Set(nsIAtom* aAttribute, const nsHTMLValue& aValue)  {    NS_IF_RELEASE(mAttribute);    mAttribute = aAttribute;    NS_IF_ADDREF(mAttribute);    mValue = aValue;  }