    function initialize() public {
        require(!initialized, "already initialized");
        owner = msg.sender;
        userMapping[GENESIS_USER_ADDRESS] = User(1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, address(0));
        initialized = true;
    }