How to mock PreferenceManager in Android?

Question

I've written a class that is using Context, third party library and SharedPreferences from PreferenceManager.

It's possible to mock Context, third party library can be mocked using some mocking framework, but what to do with PreferenceManager?

I have two methods:

    public void saveString(ThirdPartyObject obj) {
        SharedPreferences appPreferences = PreferenceManager.getDefaultSharedPreferences(mContext);
        SharedPreferences.Editor editor = appPreferences.edit();
        editor.putString(mContext.getString(R.string.preferences_string_name), obj.getString());
        editor.commit();
    }

and corresponding, that loads preferences.