def METHOD_NAME(days: Union[Days, Set[Days]]) -> str:
    """Sum the requested weekdays bit representation and return as hexadecimal value.
    Args:
        days: the requested Weekday members.
    Return:
        Hexadecimale representation of the sum of all requested days.
    """
    if days:
        if type(days) is Days:
            return "{:02x}".format(days.bit_rep)
        elif type(days) is set or len(days) == len(set(days)):  # type: ignore
            map_to_bits = map(lambda w: w.bit_rep, days)  # type: ignore
            return "{:02x}".format(int(sum(map_to_bits)))
    raise ValueError("no days requested")