Check time range

def _validate_time_range(trange, status, msg):
    '''
    Check time range
    '''
    # If trange is empty, just return the current status & msg
    if not trange:
        return status, msg

    if not isinstance(trange, dict):
        status = False
        msg = ('The time_range parameter for '
               'wtmp beacon must '
               'be a dictionary.')

    if not all(k in trange for k in ('start', 'end')):
        status = False
        msg = ('The time_range parameter for '
               'wtmp beacon must contain '
               'start & end options.')

    return status, msg