Missing vacuum line?

I had a 2011 Ecoboost willed to me by my recently deceased grandfather.

The engine seems to be running great. I was beginning to clean it up this evening and was taking a closer look at the engine. That's when I noted a nipple on the intake tube just past the air filter box that was open and empty. I looked at some pictures of 2011 ecoboosts and there was a hose there. Can anyone help me with where that hose is supposed to go.

In the pictures below, there is obviously a hose coming off the nipple. Mine is just the open nipple with no hose going anywhere.

I've circled the connection here


Here is a closer picture of the connection.


I'll try to get a picture of my actual engine tomorrow when the sun is up.



Thanks!