'Bookmark all volumes that are assigned to the hostgroup.'

def add_hg_bookmark(self, hg_name, bm_name, utc_date=None, str_date=None, bm_type=None):

    cmd = RdxApiCmd(cmd_prefix=[HG_DIR, 'add-bookmark'])
    cmd.set_argument(hg_name)
    cmd.add_flag('name', bm_name)
    if (str_date is not None):
        cmd.add_flag('timestamp', str_date)
    else:
        cmd.add_flag('timestamp', ReduxioAPI._utc_to_cli_date(utc_date))
    cmd.add_flag('type', bm_type)
    return self._run_cmd(cmd)
