private static string ToUriValueString(IUriCondition condition)
        {
            var valueLiteral = condition.ValueLiteral;

            switch (condition.ValueTypeCode)
            {
            case TypeCode.Empty: return("null");

            case TypeCode.Char:
            case TypeCode.String:
                var encoded = valueLiteral.UriEncode();
                switch (encoded)
                {
                case null: return("null");

                case "false":
                case "False":
                case "FALSE":
                case "true":
                case "True":
                case "TRUE":
                case var _ when encoded.All(char.IsDigit): return($"'{encoded}'");

                default: return(encoded);
                }

            default: return(valueLiteral);
            }
        }
        private static string ToUriString(IUriCondition condition)
        {
            if (condition == null)
            {
                return("");
            }
            var op    = ((Operator)condition.Operator).Common;
            var value = ToUriValueString(condition);

            return($"{condition.Key.UriEncode()}{op}{value}");
        }