using (FlowDbContext db = CreateContext(trans))
            {
                BillStatus? state = null;
                db.Submit(
                    billTypeId,
                    billId,
                    flowId,
                    ref state
                );
                return state.Value;
            }

    public enum BillStatus
    {
        /// <summary>
        /// 已提交未审核
        /// </summary>
        Submited = 1,
        /// <summary>
        /// 已经审核，但未完成
        /// </summary>
        Processing = 2,
        /// <summary>
        /// 通过流程的
        /// </summary>
        Passed = 3,
        /// <summary>
        /// 被否决的
        /// </summary>
        Rejected = 4
    }