The function to setup the adapter.

CoworkerListFragment.kt

    fun initializeCoworkerRecyclerView() {
        //Setup the query.
        val query = db.collection(COLLECTION_USERS).orderBy("name")
        val options = FirestoreRecyclerOptions.Builder<AppUser>().setQuery(query, AppUser::class.java).build()


        adapter = CoworkerListAdapter(options)
        val recyclerView = activity!!.findViewById<RecyclerView>(R.id.coworker_recycler_view)
        recyclerView.setHasFixedSize(true)
        recyclerView.layoutManager = LinearLayoutManager(context)
        recyclerView.adapter = adapter
        adapter.startListening()
    }