public void ConfigureServices(IServiceCollection services)
        { 
            services.AddHttpClient("v3", estClient =>
            {
                estClient.BaseAddress = new Uri("https://date.nager.at/api/v3/");
                estClient.DefaultRequestHeaders.Accept
                    .Add(new MediaTypeWithQualityHeaderValue("application/json"));
            });
            services.AddHttpClient("v2", estClient =>
            {
                estClient.BaseAddress = new Uri("https://date.nager.at/api/v2/");
                estClient.DefaultRequestHeaders.Accept
                    .Add(new MediaTypeWithQualityHeaderValue("application/json"));
            });
        }