public async Task <TickersData> TickersAsync()
        {
            TickersData data = new TickersData();

            try
            {
                HttpClient _httpClient = new HttpClient {
                    BaseAddress = new Uri(Endpoints.CoinMarketCapApiUrl)
                };
                var url      = QueryStringService.AppendQueryString(Endpoints.Ticker, new Dictionary <string, string>());
                var response = await _httpClient.GetAsync(url);

                data = await JsonParserService.ParseResponse <TickersData>(response);

                if (data == null)
                {
                    data = new TickersData
                    {
                        Data     = null,
                        Metadata = new TickerMetadata {
                            Error = int.MinValue
                        },
                        Success = false
                    };
                }
                data.Success = data.Metadata.Error == null;
            }
            catch { }

            return(data);
        }
        public async Task <TickersData> TickersAsync(int?start, int?limit, SortBy sort = SortBy.id, FiatCurrency convert = FiatCurrency.USD)
        {
            TickersData data = new TickersData();

            try
            {
                HttpClient _httpClient = new HttpClient {
                    BaseAddress = new Uri(Endpoints.CoinMarketCapApiUrl)
                };
                var url = QueryStringService.AppendQueryString(Endpoints.Ticker, new Dictionary <string, string>
                {
                    { "start", start >= 1 ? start.ToString() : null },
                    { "limit", limit >= 1 ? limit.ToString() : null },
                    { "sort", sort.ToString() },
                    { "convert", convert.ToString() }
                });
                var response = await _httpClient.GetAsync(url);

                data = await JsonParserService.ParseResponse <TickersData>(response);

                if (data == null)
                {
                    data = new TickersData
                    {
                        Data     = null,
                        Metadata = new TickerMetadata {
                            Error = int.MinValue
                        },
                        Success = false
                    };
                }
                data.Success = data.Metadata.Error == null;
            }
            catch { }

            return(data);
        }