NS_PRECONDITION(aDataBase != nsnull, "null ptr"); if (! aDataBase) return NS_ERROR_NULL_POINTER;
NS_PRECONDITION(mRoot != nsnull, "not initialized"); if (! mRoot) return NS_ERROR_NOT_INITIALIZED;
RDFGenericBuilderImpl::SetDataBase(nsIRDFCompositeDataSource* aDataBase){    NS_PRECONDITION(aDataBase != nsnull, "null ptr");    if (! aDataBase)        return NS_ERROR_NULL_POINTER;    NS_PRECONDITION(mDB == nsnull, "already initialized");    if (mDB)        return NS_ERROR_ALREADY_INITIALIZED;    mDB = aDataBase;    NS_ADDREF(mDB);    mDB->AddObserver(this);    return NS_OK;}