def string_confirmation_validator(confirmation_str: str):
    """
    Returns a validator method that returns true if the confirmation_str is in the passed string.
    :param confirmation_str: substring to locate in utterance
    :return: True if the confirmation is in the spoken utterance.
    """
    if not isinstance(confirmation_str, str):
        raise TypeError(f"Expected str, got {type(confirmation_str)}")
    if not confirmation_str:
        raise ValueError(f"Got empty confirmation string")

    def wrapped_validator(utt):
        return confirmation_str in utt
    return wrapped_validator