Erro de checagem de permissao

No curso o professor pediu para fazermos a checagem de permissao para location, porem nao estou conseguindo. Fiz o seguinte na classe Localizador.java:

@Override
    public void onConnected(@Nullable Bundle bundle) {
        LocationRequest request = new LocationRequest();
        request.setSmallestDisplacement(50);
        request.setInterval(1000);
        request.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);

        if (ActivityCompat.checkSelfPermission(context,
                Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED &&
                ActivityCompat.checkSelfPermission(context,
                        Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
            ActivityCompat.requestPermissions((ListaAlunosActivity) context,
                    new String[]{Manifest.permission.ACCESS_FINE_LOCATION,
                            Manifest.permission.ACCESS_COARSE_LOCATION}, 321);
        } else {
            LocationServices.FusedLocationApi.requestLocationUpdates(client, request, this);
        }
    }

Meu aplicativo nao esta crashando, porem nao carrega o mapa.... Socorro!!!