public Builder mergeBuyItem(JSystemPiqi.buy_item_request value) {
        if (buyItemBuilder_ == null) {
          if (((bitField0_ & 0x00000001) == 0x00000001) &&
              buyItem_ != JSystemPiqi.buy_item_request.getDefaultInstance()) {
            buyItem_ =
              JSystemPiqi.buy_item_request.newBuilder(buyItem_).mergeFrom(value).buildPartial();
          } else {
            buyItem_ = value;
          }
          onChanged();
        } else {
          buyItemBuilder_.mergeFrom(value);
        }
        bitField0_ |= 0x00000001;
        return this;
      }