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        public static bool CheckInputValidate(string input)
        {
            if (string.IsNullOrWhiteSpace(input))
                return true;

            string RestrictedCharacters = @"\|!#$%&()=?»«@£§€{};'<>_";
            var allowedExtensions = new string[] { "jpg", "png", "shp", "jpeg" };
            var extensions = input.Split(',');
            if (extensions.All(extension => allowedExtensions.Contains(extension)) == false)
                return false;
            foreach (var extension in extensions)
            {
                foreach (var character in RestrictedCharacters)
                    if (extension.Contains(character)) return false;
            }
            return true;
        }