Issues saving session objects using simple-injector - asp.net-mvc

Question

I have MVC application where I am trying to save some objects in session using DI framework of simple injector.
I register the objects as below
container.RegisterPerWebRequest<Func<HttpSessionState>>(() =>
() => HttpContext.Current.Session);
container.RegisterSingle<MemoryCache>(() => MemoryCache.Default);
container.RegisterPerWebRequest<ISessionCacheService, SessionCacheService>();
Now in the session service constructor I am able to see the multi-cast delegate for sessionstate object but when I try to add other objects I get the Object reference error. The constructor is listed below
protected internal Func<HttpSessionState> _HttpSessionState;
public SessionCacheService(Func<HttpSessionState> httpSessionState)
{
_HttpSessionState = httpSessionState;
}
I get the error in the following line of code inside a method of this service
public void Set<T>(string key, T data)
{
_HttpSessionState()[key] = data;
}
Here I can see that the following variable is null
this._HttpSessionState()
The main reason why we need to use this construct is that we need to store multicast delegate to session as shown in the example below
public RuntimeContext Current
{
get
{
Func<RuntimeContext> getRuntimeContextFunc = () =>
{
return new RuntimeContext()
{
ImpersonatingAgentId = Guid.Empty
};
};
return this._SessionCacheService.Get<RuntimeContext>(
typeof(RuntimeContext).ToString(),
getRuntimeContextFunc);
}
}
Later on we can retrieve these items from session using the get method
public T Get<T>(string key, Func<T> acquire)
{
if (this.IsSet(key))
{
return this.Get<T>(key);
}
else
{
var result = acquire();
this.Set<T>(key, result);
return result;
}
}