allow changing run name

    loss = train_params["loss"]

    cache_dir = train_params["cache_dir"]

    experiment_name = train_params.get("experiment_name", "Train_REFL_GPT")

    run_name = train_params.get("run_name", None)

    # parse model parameters

    d_model = model_params["d_model"]

    to_log = model_params.get("to_log", False)

    # set run name

    if run_name is None:

        run_name = f"gpt_d{d_model}_h{n_head}_l{num_encoder_layers}"

    # prepare data