def get_next_slug(base_value, suffix, max_length=100):
    """
    Gets the next slug from base_value such that "base_value-suffix" will not exceed max_length characters.
    """
    suffix_length = len(str(suffix)) + 1  # + 1 for the "-" character
    if suffix_length >= max_length:
        raise ValueError("Suffix {} is too long to create a unique slug! ".format(suffix))

    return '{}-{}'.format(base_value[:max_length - suffix_length], suffix)