How to use 'roles' with firebase component

Hi, my question about firebase roles/

How to use 'roles' with firebase component/ for exzmpl:

"roles" : {
"uid1" : "normal",
"uid2" : "premium",
"uid3" : "normal",
}

ref.child("roles").child(firebaseUser.getUid()).addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
String role = dataSnapshot.getValue(String.class);
// check role and replace fragment
}
@Override
public void onCancelled(DatabaseError databaseError) {}
});