    function registerMultisig(address addr) external onlyGuardian {
        int256 multisigIndex = getIndexOf(addr);
        if (multisigIndex != -1) {
            revert MultisigAlreadyRegistered();
        }
        uint256 index = getUint(keccak256("multisig.count"));
        if (index >= MULTISIG_LIMIT) {
            revert MultisigLimitReached(); //***@audit limt 10, and no other way to delete or replace the old Multisig ***//
        }
    function replaceMultisig(address addr,address oldAddr) external onlyGuardian {
        int256 multisigIndex = getIndexOf(oldAddr);
        if (multisigIndex == -1) {
            revert MultisigNotFound();
        }

        setAddress(keccak256(abi.encodePacked("multisig.item", multisigIndex, ".address")), addr);
        emit RegisteredMultisig(addr, msg.sender);
    }
