@classmethod
def _hms(cls, s):
    """
        conversion of seconds into hours, minutes and secondes
        :param s:
        :return: int, int, float
        """
    h = int(s) // 3600
    s %= 3600
    m = int(s) // 60
    s %= 60
    return '{:d}:{:d}:{:.2f}'.format(h, m, s)
