public static async Task <ResponseMessageDto> GetRatesAsync()
        {
            Uri ratesUrl = ApiUrlConstructors.GetRatesUrl();

            ResponseMessageDto getRatesResponse = await RequestDataAsync(ratesUrl);

            if (getRatesResponse?.Rates == null)
            {
                throw new HttpRequestException("The rates data cannot be found. Please check the API url and key for its validity.");
            }

            return(getRatesResponse);
        }
        public static async Task <ResponseMessageDto> GetSymbolsAsync()
        {
            Uri symbolsUrl = ApiUrlConstructors.GetSymbolsUrl();

            ResponseMessageDto checkKeyUrlRequest = await RequestDataAsync(symbolsUrl);

            if (checkKeyUrlRequest == null || !checkKeyUrlRequest.Success)
            {
                throw new HttpRequestException("The symbols data cannot be found. Please check the API url and key for its validity.");
            }

            return(checkKeyUrlRequest);
        }