def choice_of_c_constants(prev_c, **optional_args):
    """Function that returns the new constants that will be used in the iteration knowing the previous ones.
    The returned values for the two constants should be such that there are enough models to find enough parents and
    also should be bounded in ...

    Args:
        prev_c ([type]): [description]

    Returns:
        int, int: The two contants with the smaller one before and the bigger one after
    """
    c_1 = prev_c - 1 if not(prev_c == 1) else prev_c
    c_2 = prev_c + 1 if not(prev_c == 3) else prev_c
    return c_1, c_2