    if (_allowedWhitelistIndex == 0 || _whitelistIndex[to] > _allowedWhitelistIndex) {
        revert NotWhitelisted();
    }
    receive() external payable {
@>      if (_isSelfWhitelistDisabled) {
            revert SelfWhitelistDisabled();
        }
        if (_isBlacklisted[_msgSender()]) {
            revert Blacklisted();
        }
        _addWhitelistedAddress(_msgSender());
        payable(_msgSender()).transfer(msg.value);
    }
