code: public File getAsFile(String bucket, String fname) throws IOException {
      Storage.Objects.Get request = storage.objects().get(bucket, fname);
      File file = File.createTempFile("gcsdownload", "obj");
      try (OutputStream out = new FileOutputStream(file)) {
        request.executeMediaAndDownloadTo(out);
      }
      return file;
    }
docs: Retrieve the whole file (to a temporary file on disk).
  
  @throws IOException