@Override
    protected void onPause() {
        SharedPreferences sp = PreferenceManager.getDefaultSharedPreferences(this);
        sp.unregisterOnSharedPreferenceChangeListener(this);
        super.onPause();
    }
A {@link PreferenceActivity} that presents a set of application settings.
<p>
See <a href="http://developer.android.com/design/patterns/settings.html">
Android Design: Settings</a> for design guidelines and the <a
href="http://developer.android.com/guide/topics/ui/settings.html">Settings
API Guide</a> for more information on developing a Settings UI.
app/src/main/java/com/example/android/sunshine/app/SettingsActivity.java