if (! mObservers) { nsresult rv; rv = NS_NewISupportsArray(getter_AddRefs(mObservers)); if (NS_FAILED(rv)) return rv; }  mObservers->AppendElement(aObserver); return NS_OK;
if (! mObservers.AppendObject(aObserver)) { return NS_ERROR_FAILURE; }  return NS_OK;
nsBookmarksService::AddObserver(nsIRDFObserver* aObserver){	if (! aObserver)		return NS_ERROR_NULL_POINTER;	if (! mObservers) {		nsresult rv;		rv = NS_NewISupportsArray(getter_AddRefs(mObservers));		if (NS_FAILED(rv)) return rv;	}	mObservers->AppendElement(aObserver);	return NS_OK;}