model_checkpoint = ModelCheckpoint(
        "checkpoint",
        n_saved=2,
        filename_prefix="best",
        score_function=score_function,
        score_name="accuracy",
        global_step_transform=global_step_from_engine(trainer),
    )

    # Save the model after every epoch of val_evaluator is completed
    val_evaluator.add_event_handler(
        Events.COMPLETED, model_checkpoint, {"model": model}
    )