NS_IMETHOD ContentAppended(nsIDocument *aDocument, nsIContent *aContainer, PRInt32 aNewIndexInContainer) { return NS_OK; }
NS_IMPL_NSIDOCUMENTOBSERVER_CONTENT(HTMLContentSink)
  NS_IMETHOD ContentAppended(nsIDocument *aDocument, nsIContent *aContainer,                             PRInt32 aNewIndexInContainer)  {    return NS_OK;  }