code: private void downloadBitmap(final String path, final Object into, final Transformation transformation) {
          //download the bitmap from bluetooth
          new AsyncTask<Void, Void, Bitmap>() {
              @Override
              protected Bitmap doInBackground(Void... params) {
                  Bitmap bitmap = getBitmap(path);
                  Log.d(TAG, "bitmap from bluetooth " + path + " " + bitmap);
                  if (bitmap != null) {
                      Log.d(TAG, "save bitmap " + path + " into cache");
                      saveBitmap(getKey(path), bitmap);
  
                      if (transformation != null) {
                          return transformAndSaveBitmap(path, transformation);
                      }
                  }
                  return bitmap;
              }
  
              @Override
              protected void onPostExecute(Bitmap bitmap) {
                  super.onPostExecute(bitmap);
                  if (into != null)
                      returnBitmapInto(bitmap, path, into);
              }
          }.execute();
      }
docs: Download bitmap from bluetooth asset and store it into LruCache and LruDiskCache
  
  @param path the path or url of the image
  @param into the destination object