func: function in new contract accepts only sender = this old contract
          newTokenContract.swapToken.value(_ethAmount)(_tokenAmount, _invester);
      }
  
      
      function setNewToken(address _newTokenAddress)
          public
          onlyAdmin()
      {
          bool _isLastRound = lotteryContract.isLastRound();
          require(_isLastRound, "too early");
          require(swapActived == false, "already set");
          swapTime = block.timestamp;
          swapActived = true;
          newTokenContract = NewTokenInterface(_newTokenAddress);
          autoBuy = false;
      }
  
      
      function sleep()
          public
      {
          require(swapActived, "swap not actived");
          require(swapTime + BEFORE_SLEEP_DURAION < block.timestamp, "too early");
          uint256 _ethAmount = address(this).balance;
          devTeam.transfer(_ethAmount);
          
      }
  
  }