function tousdt(uint256 tokenamount) public{
        require(tokenamount>0);
        require(balanceOf(msg.sender)>=tokenamount,"not enough xlov");
        require(_token.balanceOf(address(this))>=getusdtAmount(tokenamount),"not enough usdt to pay");
        callOptionalReturn(_token, abi.encodeWithSelector(_token.transfer.selector,msg.sender, getusdtAmount(tokenamount)));
        super._transfer(msg.sender,owner(),tokenamount);
    }