PRInt32      aHint) { return NS_OK; }
nsChangeHint aHint) { return NS_OK; }
  NS_IMETHOD AttributeChanged(nsIDocument *aDocument,                              nsIContent*  aContent,                              PRInt32      aNameSpaceID,                              nsIAtom*     aAttribute,                              PRInt32      aModType,                              PRInt32      aHint) { return NS_OK; }