@staticmethod
def _range_split(s):
    """Split ID range string."""
    ab = s.split('-', 1)
    nnum_len = len(ab[0])
    a = int(ab[0])
    b = int(ab[-1])
    if a > b:
        a, b = b, a
    b = b + 1
    return a, b, nnum_len
