NS_QueryNotificationCallbacks(nsIInterfaceRequestor  *aCallbacks, nsILoadGroup           *aLoadGroup, const nsIID            &aIID, void                  **aResult)
NS_QueryNotificationCallbacks(nsIInterfaceRequestor *aCallbacks, nsILoadGroup          *aLoadGroup, nsCOMPtr<T>           &aResult)
NS_QueryNotificationCallbacks(nsIInterfaceRequestor  *aCallbacks,                              nsILoadGroup           *aLoadGroup,                              const nsIID            &aIID,                              void                  **aResult){    *aResult = nsnull;    if (aCallbacks)        aCallbacks->GetInterface(aIID, aResult);    if (!*aResult) {        // try load group's notification callbacks...        if (aLoadGroup) {            nsCOMPtr<nsIInterfaceRequestor> cbs;            aLoadGroup->GetNotificationCallbacks(getter_AddRefs(cbs));            if (cbs)                cbs->GetInterface(aIID, aResult);        }    }}