[Fact]
    public async Task Can_share_instance_between_contexts_with_sugar_experience()
    {
        using (var db = new SimpleContext())
        {
            db.Artists.Add(new SimpleContext.Artist { Name = "John Doe" });
            await db.SaveChangesAsync();
        }

        using (var db = new SimpleContext())
        {
            var data = db.Artists.ToList();
            Assert.Equal(1, data.Count);
            Assert.Equal("John Doe", data[0].Name);
        }
    }

    private class SimpleContext : EntityContext
    {
        public EntitySet<Artist> Artists { get; set; }

        protected override void OnConfiguring(EntityConfigurationBuilder builder)
        {
            builder.UseDataStore(new InMemoryDataStore());
        }

        protected override void OnModelCreating(ModelBuilder builder)
        {
            builder.Entity<Artist>().Key(a => a.ArtistId);
        }

        public class Artist : ArtistBase<string>
        {
        }

        public class ArtistBase<TKey>
        {
            public TKey ArtistId { get; set; }
            public string Name { get; set; }
        }
    }

:(
Helios failed to start.
The ApplicationStart method threw an exception. Detailed exception information is below.

System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. ---> System.TypeLoadException: Method 'get_Name' in type 'Microsoft.Data.SqlServer.SqlServerDataStoreSource' from assembly 'Microsoft.Data.SqlServer, Version=0.1.0.0, Culture=neutral, PublicKeyToken=null' does not have an implementation.
at Microsoft.Data.Entity.SqlServerEntityServicesBuilderExtensions.AddSqlServer(EntityServicesBuilder builder)
at Startup.<Configuration>b__3(EntityServicesBuilder s) in D:\K\src\MusicStore\src\MusicStore\Startup.cs:line 44
at Microsoft.AspNet.DependencyInjection.EntityServiceCollectionExtensions.AddEntityFramework(ServiceCollection serviceCollection, Action`1 nestedBuilder)
at Startup.<>c__DisplayClass0.<Configuration>b__2(ServiceCollection services) in D:\K\src\MusicStore\src\MusicStore\Startup.cs:line 44
at Microsoft.AspNet.ContainerExtensions.UseServices(IBuilder builder, Action`1 configureServices)
at Startup.Configuration(IBuilder app) in D:\K\src\MusicStore\src\MusicStore\Startup.cs:line 32
--- End of inner exception stack trace ---
at System.RuntimeMethodHandle.InvokeMethod(Object target, Object[] arguments, Signature sig, Boolean constructor)
at System.Reflection.RuntimeMethodInfo.UnsafeInvokeInternal(Object obj, Object[] parameters, Object[] arguments)
at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
at System.Reflection.MethodBase.Invoke(Object obj, Object[] parameters)
at Microsoft.AspNet.Hosting.Startup.StartupLoader.<>c__DisplayClass0.<LoadStartup>b__3(IBuilder builder)
at Microsoft.AspNet.Loader.IIS.KlrHttpApplication.HeliosStartupLoaderProvider.WrappingStartupLoader.<>c__DisplayClass0.<LoadStartup>b__2(IBuilder builder)
at Microsoft.AspNet.Hosting.HostingEngine.EnsureApplicationDelegate(HostingContext context)
at Microsoft.AspNet.Hosting.HostingEngine.Start(HostingContext context)
at Microsoft.AspNet.Loader.IIS.KlrHttpApplication.ApplicationStart(IHttpApplication application)
at Microsoft.AspNet.Loader.IIS.HttpApplicationBase.InvokeApplicationStart(IHttpApplication application)

using Microsoft.Data.Entity;
using Microsoft.Data.InMemory;

namespace ConsoleApplication54
{
    class Program
    {
        static void Main(string[] args)
        {
            using (var db = new MyContext())
            {
                db.Blogs.Add(new Blog { BlogId = 1 });
                db.Blogs.Add(new Blog { BlogId = 1 });
                db.SaveChanges();
            }
        }
    }

    public class MyContext : DbContext
    {
        public DbSet<Blog> Blogs { get; set; }

        protected override void OnConfiguring(EntityConfigurationBuilder builder)
        {
            builder.UseInMemoryStore();
        }
    }

    public class Blog
    {
        public int BlogId { get; set; }
        public string Name { get; set; }
        public string Url { get; set; }
    }
}

System.AggregateException was unhandled
  _HResult=-2146233088
  _message=One or more errors occurred.
  HResult=-2146233088
  IsTransient=false
  Message=One or more errors occurred.
  Source=mscorlib
  StackTrace:
       at System.Threading.Tasks.Task.ThrowIfExceptional(Boolean includeTaskCanceledExceptions)
       at System.Threading.Tasks.Task`1.GetResultCore(Boolean waitCompletionNotification)
       at System.Threading.Tasks.Task`1.get_Result()
       at Microsoft.Data.Entity.DbContext.Add[TEntity](TEntity entity)
       at Microsoft.Data.Entity.DbSet`1.Add(TEntity entity)
       at ConsoleApplication54.Program.Main(String[] args) in c:\Users\rowmil\Documents\Visual Studio 2013\Projects\ConsoleApplication54\ConsoleApplication54\Program.cs:line 13
       at System.AppDomain._nExecuteAssembly(RuntimeAssembly assembly, String[] args)
       at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args)
       at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
       at System.Threading.ThreadHelper.ThreadStart_Context(Object state)
       at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
       at System.Threading.ThreadHelper.ThreadStart()
  InnerException: System.InvalidOperationException
       _HResult=-2146233079
       _message=The instance of entity type 'Blog' cannot be tracked because another instance of this type with the same key is already being tracked. For new entities consider using an IIdentityGenerator to generate unique key values.
       HResult=-2146233079
       IsTransient=false
       Message=The instance of entity type 'Blog' cannot be tracked because another instance of this type with the same key is already being tracked. For new entities consider using an IIdentityGenerator to generate unique key values.
       Source=Microsoft.Data.Entity
       StackTrace:
            at Microsoft.Data.Entity.ChangeTracking.StateManager.StartTracking(StateEntry entry)
            at Microsoft.Data.Entity.ChangeTracking.StateEntry.SetEntityState(EntityState entityState, Object generatedValue)
            at Microsoft.Data.Entity.ChangeTracking.StateEntry.<SetEntityStateAsync>d__1.MoveNext()
         --- End of stack trace from previous location where exception was thrown ---
            at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
            at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
            at System.Runtime.CompilerServices.ConfiguredTaskAwaitable.ConfiguredTaskAwaiter.GetResult()
            at Microsoft.Data.Entity.DbContext.<AddAsync>d__1`1.MoveNext()
       InnerException: 

    [Fact]
    public async Task Can_create_two_artists()
    {
        using (var db = new SimpleContext())
        {
            db.Artists.Add(new SimpleContext.Artist { Name = "John Doe", ArtistId = Guid.NewGuid().ToString() });
            await db.SaveChangesAsync();
            db.Artists.Add(new SimpleContext.Artist { Name = "Second guy", ArtistId = Guid.NewGuid().ToString() });
            await db.SaveChangesAsync();
        }
    }

    private class SimpleContext : EntityContext
    {
        public EntitySet<Artist> Artists { get; set; }

        protected override void OnConfiguring(EntityConfigurationBuilder builder)
        {
            builder.UseDataStore(new InMemoryDataStore());
        }

        protected override void OnModelCreating(ModelBuilder builder)
        {
            builder.Entity<Artist>().Key(a => a.ArtistId);
        }

        public class Artist
        {
            public string ArtistId { get; set; }
            public string Name { get; set; }
        }
    }

System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. ---> System.AggregateException: One or more errors occurred. ---> System.Data.SqlClient.SqlException: A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: Named Pipes Provider, error: 40 - Could not open a connection to SQL Server) ---> System.ComponentModel.Win32Exception: Access is denied
 --- End of inner exception stack trace ---
 at System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection, Action`1 wrapCloseInAction)
 at System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj, Boolean callerHasConnectionLock, Boolean asyncClose)
 at System.Data.SqlClient.TdsParser.Connect(ServerInfo serverInfo, SqlInternalConnectionTds connHandler, Boolean ignoreSniOpenTimeout, Int64 timerExpire, Boolean encrypt, Boolean trustServerCert, Boolean integratedSecurity, Boolean withFailover)
 at System.Data.SqlClient.SqlInternalConnectionTds.AttemptOneLogin(ServerInfo serverInfo, String newPassword, SecureString newSecurePassword, Boolean ignoreSniOpenTimeout, TimeoutTimer timeout, Boolean withFailover)
 at System.Data.SqlClient.SqlInternalConnectionTds.LoginNoFailover(ServerInfo serverInfo, String newPassword, SecureString newSecurePassword, Boolean redirectedUserInstance, SqlConnectionString connectionOptions, SqlCredential credential, TimeoutTimer timeout)
 at System.Data.SqlClient.SqlInternalConnectionTds.OpenLoginEnlist(TimeoutTimer timeout, SqlConnectionString connectionOptions, SqlCredential credential, String newPassword, SecureString newSecurePassword, Boolean redirectedUserInstance)
 at System.Data.SqlClient.SqlInternalConnectionTds..ctor(DbConnectionPoolIdentity identity, SqlConnectionString connectionOptions, SqlCredential credential, Object providerInfo, String newPassword, SecureString newSecurePassword, Boolean redirectedUserInstance, SqlConnectionString userConnectionOptions, SessionData reconnectSessionData)
 at System.Data.SqlClient.SqlConnectionFactory.CreateConnection(DbConnectionOptions options, DbConnectionPoolKey poolKey, Object poolGroupProviderInfo, DbConnectionPool pool, DbConnection owningConnection, DbConnectionOptions userOptions)
 at System.Data.ProviderBase.DbConnectionFactory.CreatePooledConnection(DbConnectionPool pool, DbConnection owningObject, DbConnectionOptions options, DbConnectionPoolKey poolKey, DbConnectionOptions userOptions)
 at System.Data.ProviderBase.DbConnectionPool.CreateObject(DbConnection owningObject, DbConnectionOptions userOptions, DbConnectionInternal oldConnection)
 at System.Data.ProviderBase.DbConnectionPool.UserCreateRequest(DbConnection owningObject, DbConnectionOptions userOptions, DbConnectionInternal oldConnection)
 at System.Data.ProviderBase.DbConnectionPool.TryGetConnection(DbConnection owningObject, UInt32 waitForMultipleObjectsTimeout, Boolean allowCreate, Boolean onlyOneCheckConnection, DbConnectionOptions userOptions, DbConnectionInternal& connection)
 at System.Data.ProviderBase.DbConnectionPool.WaitForPendingOpen()
--- End of stack trace from previous location where exception was thrown ---
 at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
 at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
 at System.Runtime.CompilerServices.TaskAwaiter.GetResult()
 at Microsoft.Data.Entity.Relational.RelationalConnection.<OpenAsync>d__1.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
 at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
 at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
 at System.Runtime.CompilerServices.TaskAwaiter.GetResult()
 at Microsoft.Data.Entity.SqlServer.SqlServerDataStoreCreator.<ExistsAsync>d__1.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
 at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
 at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
 at System.Runtime.CompilerServices.TaskAwaiter`1.GetResult()
 at MusicStore.Models.SampleData.<InitializeMusicStoreDatabaseAsync>d__1.MoveNext() in D:\home\site\wwwroot\MusicStore\Models\SampleData.cs:line 22

   Microsoft.AspNet.Identity.Entity.Test.UserStoreTest.CanCreateUserUsingEF [FAIL]
      System.AggregateException : One or more errors occurred.\r\n---- System.Data.SqlClient.SqlException : The paramet
rized query '(@p0 nvarchar(4000),@p1 int,@p2 nvarchar(4000),@p3 nvarchar(4000' expects the parameter '@p0', which was n
t supplied.
      Stack Trace:
            at System.Threading.Tasks.Task.ThrowIfExceptional(Boolean includeTaskCanceledExceptions)
            at System.Threading.Tasks.Task`1.GetResultCore(Boolean waitCompletionNotification)
            at System.Threading.Tasks.Task`1.get_Result()
            at Microsoft.Data.Entity.DbContext.SaveChanges()
            at Microsoft.AspNet.Identity.Entity.Test.UserStoreTest.CanCreateUserUsingEF() in C:\GitHub\Identity\test\Mi
rosoft.AspNet.Identity.Entity.Test\UserStoreTest.cs:line 49
         ----- Inner Stack Trace -----

  System.NotSupportedException : Specified method is not supported.
  Stack Trace:
        at Microsoft.Data.SqlServer.SqlServerMigrationOperationSqlGenerator.GenerateDataType(Column column)
        at Microsoft.Data.Migrations.MigrationOperationSqlGenerator.GenerateColumn(Column column, IndentedStringBuil

builder.Entity<Photo>().Key(
    p => p.PhotoId).ForeignKeys(
        o => o.ForeignKey<Gallery>(
            p => p.Gallery));

Compilation Error 
  Description: An error occurred during the compilation of a resource required to service this request. Please review the following specific error details and modify your source code appropriately. 

 Compiler Error Message: CS0012: The type 'System.Object' is defined in an assembly that is not referenced. You must add a reference to assembly 'System.Runtime, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a'.

  <system.web>
    ...
    <compilation ...>
      <assemblies>
        <add assembly="System.Runtime, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a"/>
      </assemblies>
    </compilation>
  </system.web>

using Microsoft.Data.Entity;
using Microsoft.Data.SqlServer;

namespace ConsoleApplication54
{
    class Program
    {
        static void Main(string[] args)
        {
            using (var db = new MyContext())
            {
                if(!db.Database.Exists())
                {
                    db.Database.Create();
                }

                db.Blogs.Add(new Blog { Name = "Test", Url = "test.com" });
                db.SaveChanges();
            }
        }
    }

    public class MyContext : DbContext
    {
        public DbSet<Blog> Blogs { get; set; }

        protected override void OnConfiguring(EntityConfigurationBuilder builder)
        {
            builder.SqlServerConnectionString(@"Server=(localdb)\v11.0;Database=MyDatabase;Trusted_Connection=True;");
        }
    }

    public class Blog
    {
        public int BlogId { get; set; }
        public string Name { get; set; }
        public string Url { get; set; }
    }
}

System.AggregateException was unhandled
  _HResult=-2146233088
  _message=One or more errors occurred.
  HResult=-2146233088
  IsTransient=false
  Message=One or more errors occurred.
  Source=mscorlib
  StackTrace:
       at System.Threading.Tasks.Task.ThrowIfExceptional(Boolean includeTaskCanceledExceptions)
       at System.Threading.Tasks.Task`1.GetResultCore(Boolean waitCompletionNotification)
       at System.Threading.Tasks.Task`1.get_Result()
       at Microsoft.Data.Entity.DbContext.SaveChanges()
       at ConsoleApplication54.Program.Main(String[] args) in c:\Users\rowmil\Documents\Visual Studio 2013\Projects\ConsoleApplication54\ConsoleApplication54\Program.cs:line 18
       at System.AppDomain._nExecuteAssembly(RuntimeAssembly assembly, String[] args)
       at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args)
       at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
       at System.Threading.ThreadHelper.ThreadStart_Context(Object state)
       at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
       at System.Threading.ThreadHelper.ThreadStart()
  InnerException: System.InvalidOperationException
       _HResult=-2146233079
       _message=The connection was not closed. The connection's current state is open.
       HResult=-2146233079
       IsTransient=false
       Message=The connection was not closed. The connection's current state is open.
       Source=System.Data
       StackTrace:
            at System.Data.ProviderBase.DbConnectionInternal.TryOpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory, TaskCompletionSource`1 retry, DbConnectionOptions userOptions)
            at System.Data.SqlClient.SqlConnection.TryOpenInner(TaskCompletionSource`1 retry)
            at System.Data.SqlClient.SqlConnection.TryOpen(TaskCompletionSource`1 retry)
            at System.Data.SqlClient.SqlConnection.OpenAsync(CancellationToken cancellationToken)
         --- End of stack trace from previous location where exception was thrown ---
            at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
            at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
            at System.Runtime.CompilerServices.TaskAwaiter.GetResult()
            at Microsoft.Data.Relational.RelationalConnection.<OpenAsync>d__1.MoveNext()
         --- End of stack trace from previous location where exception was thrown ---
            at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
            at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
            at System.Runtime.CompilerServices.TaskAwaiter.GetResult()
            at Microsoft.Data.Relational.RelationalDataStore.<SaveChangesAsync>d__1.MoveNext()
         --- End of stack trace from previous location where exception was thrown ---
            at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
            at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
            at System.Runtime.CompilerServices.ConfiguredTaskAwaitable`1.ConfiguredTaskAwaiter.GetResult()
            at Microsoft.Data.Entity.ChangeTracking.StateManager.<SaveChangesAsync>d__1.MoveNext()
       InnerException: 

public class User {
    public string Id { get; set; }
}

public class UserContext {
    public DbSet<User> Users { get; set; }
}

var context = new UserContext();
context.Database.Create(); <--- blows up

This worked if I changed the key to int instead.