@Override
    public void clearMemory() {
        if (Log.isLoggable(TAG, Log.DEBUG)) {
            Log.d(TAG, "clearMemory");
        }
        trimToSize(0);
    }
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