RavenDB Transform not able to access dictionary property

RavenDB-transform-issue.cs

using System;
using System.Collections.Generic;
using Microsoft.VisualStudio.TestTools.UnitTesting;
using Raven.Client.Embedded;
using Raven.Client.Indexes;
using Raven.Client.Linq;
using Raven.Client;
using System.Linq;
using Raven.Abstractions.Indexing;

namespace RavenTest
{

    [TestClass]
    public class DictionaryTests 
    {
        Product[] sampleData = new [] 
        { 
            new Product 
            { 
                Id = "products/1", 
                Name = "A", 
                Specials = new Dictionary<SpecialType,string> 
                { 
                    { SpecialType.Something1, "A1" }
                }, 
                DefaultOffer=SpecialType.Something1
            },

            new Product 
            { 
                Id = "products/2", 
                Name = "B", 
                Specials = new Dictionary<SpecialType, string> 
                { 
                    { SpecialType.Something2, "B2" } 
                }, 
                DefaultOffer = SpecialType.Something2 
            },

            new Product 
            { 
                Id = "products/3", 
                Name = "C", 
                Specials = new Dictionary<SpecialType, string> { }, 
                DefaultOffer = SpecialType.None 
            }
        };


        [TestMethod]
        public void ProjectViaTransform()
        {
            using (var documentStore = this.GetDocumentStore())
            {
                documentStore.ExecuteIndex(new ProductSummariesViaTransform());

                // Now query and trasnform
                using (var session = documentStore.OpenSession())
                {
                    var result = session.Query<Product, ProductSummariesViaTransform>()
                    .Customize(x => x.WaitForNonStaleResults())
                    .AsProjection<ProductSummary>()
                    .ToList();

                    Assert.AreEqual(3, result.Count);
                    Assert.AreEqual("B2", result.First(x => x.Id == "products/2").SpecialOffer);
                    Assert.AreEqual("B", result.First(x => x.Id == "products/2").Name);
                    Assert.IsNotNull(result.FirstOrDefault(x => x.SpecialOffer == null));
                }

            }
        }

        private EmbeddableDocumentStore GetDocumentStore()
        {
            var documentStore = new EmbeddableDocumentStore { RunInMemory = true };
            documentStore.Initialize();
            // Store some documents
            using (var session = documentStore.OpenSession())
            {
                foreach (var p in sampleData)
                    session.Store(p);
                session.SaveChanges();
            }
            return documentStore;
        }

        public class ProductSummariesViaTransform : AbstractIndexCreationTask<Product>
        {
            public ProductSummariesViaTransform()
            {
                Map = products => from p in products
                                  select new { p.Name };

                TransformResults = (db, products) =>
                                    from product in products
                                    let p = db.Load<Product>(product.Id)
                                    select new
                                    {
                                        Id = product.Id,
                                        Name = product.Name,
                                        SpecialOffer = p.Specials[p.DefaultOffer]
                                    };
            }
        }

        public class Product
        {
            public string Id { get; set; }
            public string Name { get; set; }
            public SpecialType DefaultOffer { get; set; }
            public Dictionary<SpecialType, string> Specials { get; set; }
        }

        public class ProductSummary
        {
            public string Id { get; set; }
            public string Name { get; set; }
            public string SpecialOffer { get; set; }
        }

        public enum SpecialType
        {
            None = 0,
            Something1,
            Something2
        }
    }
}