def _prepare_round_config(round: str, round_config: dict) -> dict:
    """Internal function that combines a base config with a specific
    round config.

    The base config is updated with the round config,
    overwriting any common fields.

    Parameters
    ----------
    round : str
    round_config : dict

    Returns
    -------
    dict

    Raises
    ------
    ValueError
        Raises an error if the resulting config dict is empty. Typically due
        to typos in the config file.
    """
    config = {}

    if "Base" in round_config:
        config.update(round_config["Base"])

    if round in round_config:
        config.update(round_config[round])

    if not config:
        raise ValueError(f"Invalid configuration for round {round}")

    return config