[Demonstration 1]

[Buggy Method]
public void hide(long duration, final AnimationListener listener) {
    overlay.animate().alpha(0).setDuration(duration).setInterpolator(interpolator).setListener(new AnimatorListenerAdapter() {

        @Override
        public void onAnimationStart(Animator animation) {
            if (listener != null) {
                listener.onStart();
            }
        }

        @Override
        public void onAnimationEnd(android.animation.Animator animation) {
            overlay.setVisibility(View.GONE);
            if (listener != null) {
                listener.onEnd();
            }
        }
    }).start();
}

[Buggy Hunk]
public void onAnimationEnd(android.animation.Animator animation) {

[Patch]
public void onAnimationEnd(Animator animation) {

[Demonstration 2]

[Buggy Method]
private void setUnreadCount(TextView targetView, Element rawContainer) {
    if (rawContainer != null) {
        try {
            int count = NumberFormat.getNumberInstance(Locale.US).parse(rawContainer.text()).intValue();
            if (count > 100) {
                targetView.setText(getString(R.string.menu_unread_count_over100));
            } else {
                targetView.setText(String.valueOf(count));
            }
            targetView.setVisibility(View.VISIBLE);
        } catch (Exception e) {
            targetView.setText("");
            targetView.setVisibility(View.GONE);
        }
    } else {
        targetView.setText("");
        targetView.setVisibility(View.GONE);
    }
}

[Buggy Hunk]
if (rawContainer != null) {

[Patch]
if (rawContainer != null && targetView != null) {

[Demonstration 3]

[Buggy Method]
private void setupNavigationView(@Nullable Bundle savedInstanceState) {
    NavigationView navigationView = (NavigationView) findViewById(R.id.navigation_view);
    if (savedInstanceState == null) {
        navigationView.setCheckedItem(R.id.navigation_view_category_all);
    }
    navigationView.setNavigationItemSelectedListener(menuItem -> {
        SourcesCategoryFiltering category = null;
        SourcesLanguageFiltering language = null;
        SourcesCountryFiltering country = null;
        int titleRes = R.string.app_name;
        switch(menuItem.getItemId()) {
            // categories
            case R.id.navigation_view_category_all:
                category = SourcesCategoryFiltering.CATEGORY_ALL;
                titleRes = R.string.navigation_view_category_all;
                break;
            case R.id.navigation_view_category_business:
                category = SourcesCategoryFiltering.CATEGORY_BUSINESS;
                titleRes = R.string.navigation_view_category_business;
                break;
            case R.id.navigation_view_category_entertainment:
                category = SourcesCategoryFiltering.CATEGORY_ENTERTAINMENT;
                titleRes = R.string.navigation_view_category_entertainment;
                break;
            case R.id.navigation_view_category_gaming:
                category = SourcesCategoryFiltering.CATEGORY_GAMING;
                titleRes = R.string.navigation_view_category_gaming;
                break;
            case R.id.navigation_view_category_general:
                category = SourcesCategoryFiltering.CATEGORY_GENERAL;
                titleRes = R.string.navigation_view_category_general;
                break;
            case R.id.navigation_view_category_music:
                category = SourcesCategoryFiltering.CATEGORY_MUSIC;
                titleRes = R.string.navigation_view_category_music;
                break;
            case R.id.navigation_view_category_politics:
                category = SourcesCategoryFiltering.CATEGORY_POLITICS;
                titleRes = R.string.navigation_view_category_politics;
                break;
            case R.id.navigation_view_category_science_and_nature:
                category = SourcesCategoryFiltering.CATEGORY_SCIENCE_AND_NATURE;
                titleRes = R.string.navigation_view_category_science_and_nature;
                break;
            case R.id.navigation_view_category_sport:
                category = SourcesCategoryFiltering.CATEGORY_SPORT;
                titleRes = R.string.navigation_view_category_sport;
                break;
            case R.id.navigation_view_category_technology:
                category = SourcesCategoryFiltering.CATEGORY_TECHNOLOGY;
                titleRes = R.string.navigation_view_category_technology;
                break;
            // languages
            case R.id.navigation_view_language_all:
                language = SourcesLanguageFiltering.LANGUAGE_ALL;
                titleRes = R.string.navigation_view_language_all;
                break;
            case R.id.navigation_view_language_en:
                language = SourcesLanguageFiltering.LANGUAGE_ENGLISH;
                titleRes = R.string.navigation_view_language_en;
                break;
            case R.id.navigation_view_language_de:
                language = SourcesLanguageFiltering.LANGUAGE_GERMAN;
                titleRes = R.string.navigation_view_language_de;
                break;
            case R.id.navigation_view_language_fr:
                language = SourcesLanguageFiltering.LANGUAGE_FRENCH;
                titleRes = R.string.navigation_view_language_fr;
                break;
            // countries
            case R.id.navigation_view_country_all:
                country = SourcesCountryFiltering.COUNTRY_ALL;
                titleRes = R.string.navigation_view_country_all;
                break;
            case R.id.navigation_view_country_au:
                country = SourcesCountryFiltering.COUNTRY_AUSTRALIA;
                titleRes = R.string.navigation_view_country_au;
                break;
            case R.id.navigation_view_country_de:
                country = SourcesCountryFiltering.COUNTRY_GERMANY;
                titleRes = R.string.navigation_view_country_de;
                break;
            case R.id.navigation_view_country_gb:
                country = SourcesCountryFiltering.COUNTRY_GREAT_BRITAIN;
                titleRes = R.string.navigation_view_country_gb;
                break;
            case R.id.navigation_view_country_in:
                country = SourcesCountryFiltering.COUNTRY_INDIA;
                titleRes = R.string.navigation_view_country_in;
                break;
            case R.id.navigation_view_country_it:
                country = SourcesCountryFiltering.COUNTRY_ITALY;
                titleRes = R.string.navigation_view_country_it;
                break;
            case R.id.navigation_view_country_us:
                country = SourcesCountryFiltering.COUNTRY_UNITED_STATES;
                titleRes = R.string.navigation_view_country_us;
                break;
        }
        mSourcesPresenter.setCategoryFiltering(category);
        mSourcesPresenter.setLanguageFiltering(language);
        mSourcesPresenter.setCountryFiltering(country);
        mSourcesPresenter.loadSources();
        mDrawerLayout.closeDrawer(GravityCompat.START);
        mToolbarTitle = getString(titleRes);
        mToolbar.setTitle(mToolbarTitle);
        return true;
    });
}

[Buggy Hunk]
mToolbar.setTitle(mToolbarTitle);

[Patch]
getSupportActionBar().setTitle(mToolbarTitle);