public CurrencyClient(CurrencyClientConfig clientConfig)
 => _clientConfig = clientConfig;
        public static void ConfigureBussinesServices(this IServiceCollection services, CurrencyClientConfig clientConfig)
        {
            services.AddSingleton(clientConfig);

            services.AddScoped <ICurrencyService, CurrencyService>();
            services.AddScoped <ICurrencyClient, CurrencyClient>();
        }