@Override
        public void add(Bitmap bitmap) {
            if (bitmaps.contains(bitmap)) {
                throw new IllegalStateException("Can't add already added bitmap: " + bitmap + " [" + bitmap.getWidth()
                        + "x" + bitmap.getHeight() + "]");
            }
            bitmaps.add(bitmap);
        }
Constructor for LruBitmapPool.

@param maxSize The initial maximum size of the pool in bytes.
@param allowedConfigs A white listed set of {@link Bitmap.Config} that are allowed to be put
                      into the pool. Configs not in the allowed set will be rejected.
core/src/main/java/com/bumptech/glide/load/engine/bitmap_recycle/LruBitmapPool.java