Creating the bootstrapper

To configure the dependency injection and initialize the resolver, we will create a bootstrapper. We will have one shared bootstrapper and other bootstrappers for each platform to meet their specific configurations. The reason that we need them to be platform-specific is that we will have different implementations of IPhotoImporter on iOS and Android. To create a bootstrapper, we take the following steps:

1. Create a new class in the GalleryApp project and name it Bootstrapper.
2. Add the following code to the new class:

using System.Linq;
using System.Reflection;
using Autofac;
using GalleryApp.ViewModels;
using Xamarin.Forms;

namespace GalleryApp
{
    public class Bootstrapper
    {
        protected ContainerBuilder ContainerBuilder { get; 
         private set; }
        public Bootstrapper()
        {
            Initialize();
            FinishInitialization();
        }

        protected virtual void Initialize()
        {
            ContainerBuilder...