MeuDependencyResolver.cs

public class MeuDependencyResolver : IDependencyResolver
{
    private ILookup<Type, object> lookup;
    private HashSet<object> dependencias = new HashSet<object>();

    public MeuDependencyResolver()
    {
        this.dependencias.Add(new DummyDependencia1());
        this.dependencias.Add(new DummyDependencia2());
        this.dependencias.Add(new DummyDependencia2_2());

        this.lookup = this.dependencias.ToLookup(x => x.GetType());
    }

    public object GetService(Type serviceType)
    {
        return lookup[serviceType].FirstOrDefault();
    }

    public IEnumerable<object> GetServices(Type serviceType)
    {
        return lookup[serviceType];
    }
}