How to have responsive hamburger menu and brand logo with boot strap v4 alpha

If you look into nav bar documentations of boot strap 4 you will notice the responsive  nav bar with hamburger menu like we used to have in boot strap 3 is missing.

The nav bars in version 4 are having different UX. In my opinion, there are so many sites based on boot strap 3 navbar and people get used to the way it is working. 
I personally would  prefer to stick with what people are used to than introducing new way of nav bar.

Here is the sample that you need to follow