SupportedMapfragment getMapAsync ruft nicht onMapady auf

public abstract class MyMapFragment extends Fragment implements OnMapReadyCallback
{
  //
  public GoogleMap googleMap;
  SupportMapFragment mapFragment;


  @IdRes
  public abstract int getSupportMapFragId();


  @Override
  public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
     super.onViewCreated(view, savedInstanceState);
        // EDIT: http://stackoverflow.com/a/36592000/5102206
        if (android.os.Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP){
            // Do something for lollipop and above versions
            mapFragment = (SupportMapFragment) getChildFragmentManager().findFragmentById(getSupportMapFragId());
            mapFragment.getMapAsync(this);
        } else {
            // do something for phones running an SDK before lollipop
            mapFragment = (SupportMapFragment) getFragmentManager().findFragmentById(getSupportMapFragId());
            mapFragment.getMapAsync(this);
        };
  }


//..


  @Override
  public void onMapReady(GoogleMap map) {
     this.googleMap = map;
  }
}