How to get _sessionID in asp.net 5?

I have a scenario where I need to get the common session across the asp.net 5 mvc 6 application. I am doing an ecommerce application where I need to update cart of an anonymous user to registered user when user logs in within that session.I need session ID like HttpContext.Current.Session.SessionID.ToString() prior asp.net 5. I have read the below article but it doesnot mention how to get session ID. http://www.mikesdotnetting.com/article/270/sessions-in-asp-net-5

I would be grateful if  better solution is provided.