def time_a_while_ago(days=0, seconds=0, microseconds=0, milliseconds=0,
                     minutes=0, hours=0, weeks=0):
    delta = timedelta(days, seconds, microseconds, milliseconds,
                      minutes, hours, weeks)
    return datetime.utcnow() - delta
format of timedelta::
dataset/ETHPy150Open rohe/pyoidc/src/oic/utils/time_util.py/time_a_while_ago