func: function getBackLendingItem(uint64 _objId) isActive external {
          EtheremonTradeData monTradeData = EtheremonTradeData(tradingMonDataContract);
          BorrowItem memory borrowItem;
          (borrowItem.index, borrowItem.owner, borrowItem.borrower, borrowItem.price, borrowItem.lent, borrowItem.createTime, borrowItem.releaseTime) = monTradeData.getBorrowInfo(_objId);
          
          if (borrowItem.index == 0)
              revert();
          if (borrowItem.lent == false)
              revert();
          if (borrowItem.releaseTime > block.timestamp)
              revert();
          
          if (msg.sender != borrowItem.owner)
              revert();
          
          monTradeData.removeBorrowingItem(_objId);
          
          EtheremonDataBase data = EtheremonDataBase(dataContract);
          data.removeMonsterIdMapping(borrowItem.borrower, _objId);
          data.addMonsterIdMapping(msg.sender, _objId);
          EtheremonMonsterNFTInterface monsterNFT = EtheremonMonsterNFTInterface(monsterNFTContract);
          monsterNFT.triggerTransferEvent(borrowItem.borrower, msg.sender, _objId);
          
          monTradeData.removeItemLendingList(msg.sender, _objId);
          EventGetBackItem(msg.sender, borrowItem.borrower, _objId);
      }