public List <int> VerifyGroup()
        {
            var errors = new List <int>();

            if (Group == null)
            {
                return(errors);
            }

            Group = Group.Trim().Replace(HidroConstants.WHITE_SPACE, string.Empty);
            if (string.IsNullOrWhiteSpace(Group))
            {
                Group = null;
                return(errors);
            }

            if (!HelperProvider.IsNumber(Group))
            {
                errors.Add(21);
            }

            if (Group.Length > 30)
            {
                errors.Add(22);
            }

            return(errors);
        }