```build.favsDao().getAllFavs() .o...

# room

[Kulwinder Singh]

build.favsDao().getAllFavs()
                .observe(this, android.arch.lifecycle.Observer {
                    if (it != null) {
                        favs.clear()
                        favs.addAll(it)
                        mAdapter.swap(it.map { it.song } as MutableList<Song>)
                    }
                })