code: @Override
      protected void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
  
          setContentView(R.layout.activity_main);
          ButterKnife.bind(this);
  
          ImageGalleryActivity.setImageThumbnailLoader(this);
          ImageGalleryFragment.setImageThumbnailLoader(this);
          FullScreenImageGalleryActivity.setFullScreenImageLoader(this);
  
          // optionally set background color using Palette for full screen images
          paletteColorType = PaletteColorType.VIBRANT;
      }
docs: region Lifecycle Methods