Part of the https://gist.github.com/jasongaylord/df33fe4cd4bc7d253a10c3cdccc41104#file-default-cshtml

ServiceCollectionExtensions.cs

using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection.Extensions;
using TwitterViewComponent;

namespace Microsoft.Extensions.DependencyInjection
{
  public static class ServiceCollectionExtensions
  {
    public static IServiceCollection AddTwitter(this IServiceCollection services, IConfiguration configuration = null)
    {
      if (configuration != null)
        services.Configure<TwitterOptions>(configuration);
      else
        services.TryAddSingleton<TwitterOptions, TwitterOptions>();

      services.TryAddScoped<ITwitterService, TwitterService>();

      return services;
    }
  }
}