How can I get the key of the FirebaseRecyclerAdapter at populateViewHolder?

Question

I have a Firebase database with a JSON structure like this:

JSON

root:{
  "users":{
    *push1*:{
      "name":"foo1",
      "email":"bar1"
    },
    *push2*:{
      "name":"foo2",
      "email":"bar2"
    }
  }
}

In order to populate a RecyclerView, I am using the FirebaseRecyclerViewAdapter class at FirebaseUI. The problem is that I can access both "name" and "email", but in addition I need to know the *push* string (something like -KHjGvJ7o-UBxOVGpojI), which I don't manage to get.

Is there any way to get the key of the reference, instead of just the value?

What I'm trying to do is adding a new value to the JSON, leaving it like:

"users":{
  *push*:{
    "name":"foo",
    "email":"bar",
    "phone":"whatever"
  }
}

Just in case it is easier to get the reference rather than the key to generate it.

Thanks!