public IEnumerable <ValidationResult> Validate(ValidationContext validationContext)
        {
            var results = new List <ValidationResult>();

            if (GroupId.IsNot24BitHex())
            {
                results.Add(new ValidationResult($"{nameof(GroupId)} must be a valid 24-bit hex string.", new[] { nameof(GroupId) }));
            }

            if (RegionId.IsNot24BitHex())
            {
                results.Add(new ValidationResult($"{nameof(RegionId)} must be a valid 24-bit hex string.", new[] { nameof(RegionId) }));
            }

            return(results);
        }