You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: xact_callback_tests.rs
    path of file: ./repos/pgrx/pgrx-tests/src/tests
    
    the code of the file until where you have to start completion: //LICENSE Portions Copyright 2019-2021 Zombo
    
    fn make_idea_happy() {}

    #[pg_test]
    fn test_xact_callback() {
        register_xact_callback(PgXactCallbackEvent::Abort, || info!("TESTMSG: Called on abort"));
    }
}