    function addBlacklistAddress(address[] calldata users) external onlyRole(BLACKLIST_MANAGER_ROLE) {
        for (uint8 i = 0; i < users.length; i++) {
            _grantRole(BLACKLISTED_ROLE, users[i]);
        }
    }
    function addWhitelistAddress(address[] calldata users) external onlyRole(WHITELIST_MANAGER_ROLE) {
        for (uint8 i = 0; i < users.length; i++) {
            _grantRole(WHITELISTED_ROLE, users[i]);
        }
    }
        } else if (
            hasRole(WHITELISTED_ROLE, msg.sender) &&
            hasRole(WHITELISTED_ROLE, from) &&
            hasRole(WHITELISTED_ROLE, to) &&
            !hasRole(BLACKLISTED_ROLE, msg.sender) &&
L206:       !hasRole(BLACKLISTED_ROLE, from) &&
            !hasRole(BLACKLISTED_ROLE, to)
        ) {
            // n.b. an address can be whitelisted and blacklisted at the same time
            // normal case
        } else {
            revert OperationNotAllowed();
        }
    function addBlacklistAddress(address[] calldata users) external onlyRole(BLACKLIST_MANAGER_ROLE) {
        for (uint8 i = 0; i < users.length; i++) {
+           if (hasRole(WHITELISTED_ROLE, users[i]))
+               _revokeRole(WHITELISTED_ROLE, users[i]);
            _grantRole(BLACKLISTED_ROLE, users[i]);
        }
    }
    
    function addWhitelistAddress(address[] calldata users) external onlyRole(WHITELIST_MANAGER_ROLE) {
        for (uint8 i = 0; i < users.length; i++) {
+           if (hasRole(BLACKLISTED_ROLE, users[i]))
+               _revokeRole(BLACKLISTED_ROLE, users[i]);
            _grantRole(WHITELISTED_ROLE, users[i]);
        }
    }
