如何实例化扩展AndroidViewModel的ViewModel？

public class MyViewModel extends AndroidViewModel {
    // 在这里定义ViewModel的数据和逻辑
}

public class MyViewModel extends AndroidViewModel {
    private MutableLiveData<String> data;

    public MyViewModel(Application application) {
        super(application);
        // 初始化数据
        data = new MutableLiveData<>();
        data.setValue("Hello, ViewModel!");
    }

    public LiveData<String> getData() {
        return data;
    }

    public void updateData(String newData) {
        data.setValue(newData);
    }
}

public class MainActivity extends AppCompatActivity {
    private MyViewModel viewModel;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        // 获取ViewModel实例
        viewModel = new ViewModelProvider(this).get(MyViewModel.class);

        // 观察数据变化
        viewModel.getData().observe(this, new Observer<String>() {
            @Override
            public void onChanged(String newData) {
                // 更新UI
                textView.setText(newData);
            }
        });
    }
}