code: public static void init(@NonNull final Context context, IInnerImageSetter innerImageSetter,
          Class<? extends ImageView> imageClazz) {
          if (sInitialized) {
              return;
          }
          //noinspection ConstantConditions
          Preconditions.checkArgument(context != null, "context should not be null");
          Preconditions
              .checkArgument(innerImageSetter != null, "innerImageSetter should not be null");
          Preconditions.checkArgument(imageClazz != null, "imageClazz should not be null");
          TangramViewMetrics.initWith(context.getApplicationContext());
          ImageUtils.sImageClass = imageClazz;
          ImageUtils.setImageSetter(innerImageSetter);
          sInitialized = true;
      }
docs: init global Tangram environment.
  @param context the app context
  @param innerImageSetter an ImagerSetter to load image, see {@link ImageUtils}
  @param imageClazz a custom ImageView class, used to construct an imageView instance.