require(user != address(0), "KYC status for address(0) not allowed")
79:  function addKYCAddressViaSignature(
80:    uint256 kycRequirementGroup,
81:    address user,
82:    uint256 deadline,
83:    uint8 v,
84:    bytes32 r,
85:    bytes32 s
86:  ) external {
