```\nfunction addLiquidity() external payable onlyOwner {\n    uint256 tokensToAdd = (_balances[address(this)] * msg.value) /\n        liquidity;\n    require(_balances[msg.sender] >= tokensToAdd, "Not enough tokens!");\n\n    uint256 oldLiq = liquidity;\n    liquidity = liquidity + msg.value;\n    _balances[address(this)] += tokensToAdd;\n    _balances[msg.sender] -= tokensToAdd;\n    liqConst = (liqConst * liquidity) / oldLiq;\n\n    emit Transfer(msg.sender, address(this), tokensToAdd);\n}\n```\n