public class Assets {

        public final AssetManager manager = new AssetManager();
        private ObjectMap<String, Texture> textures;
        private ObjectMap<String, Sound> sounds;
        public  final String background = "test.jpg";

    public void AssetsLoad() {
        textures = new ObjectMap<String, Texture>();
        sounds = new ObjectMap<String, Sound>();
        manager.load(background, Texture.class);

    }

    public boolean update() {
        boolean done = manager.update();
        if (done) {
            finishLoading();
            Gdx.app.log("assets", "1");
        }
        return done;
    }

    private void finishLoading() {
        textures.put(background, manager.get(background, Texture.class));
    }

    public Texture getTexture(String name) {
        return textures.get(name);
    }
        public void dispose()    {
            manager.clear();

        }
    }

---------------
Fetching texture:
public class MainScreen implements Screen {

    TombStone game;
    Viewport view;
    StoneScreen ss;
    private Stage stage;
    private TextureAtlas atlas, atlasS, atlasEdit;
    private Skin skin, skinS,skinEdit;
    private Table table;
    ImageButton buttonStart, btnStore, btnMemories;
    public Texture background, btnStoreTex, btnStoreDownTex, btnStonesTex, btnStonesDownTex, btnMemoriesDownTex, btnMemoriesTex;
    public String name;
    OrthographicCamera camera;
    public  final int screenWidth = 1000;
    private  final int screenHeight = 2000;
    public Assets assets;
    public MainScreen(TombStone gam) {
        game = gam;
        assets = new Assets();
        loadStore();
        camera = new OrthographicCamera(screenWidth,screenHeight);
        view = new StretchViewport(screenWidth, screenHeight, camera);
        view.apply();
        camera.translate(camera.viewportWidth / 2, camera.viewportHeight / 2);
    }

    public void loadStore()  {
        background = assets.getTexture(assets.background);
    }



    @Override
    public void render(float delta) {

        camera.update();

        game.batch.setProjectionMatrix(camera.combined);

        game.batch.begin();

        game.batch.draw(background, 0, 0, 1000, 2000);

        game.batch.end();

    }

    @Override
    public void resize(int width, int height) {

        view.update(width, height, true);


    }
    @Override
    public void show() {

    }

    @Override
    public void hide() {
        // TODO Auto-generated method stub

    }

    @Override
    public void pause() {
        // TODO Auto-generated method stub

    }

    @Override
    public void resume() {
        // TODO Auto-generated method stub

    }

    @Override
    public void dispose() {
        // TODO Auto-generated method stub
        background.dispose();


    }


}