code: public Page<Blob> listBlobsWithDirectoryAndPrefix(String bucketName, String directory) {
      // [START listBlobsWithDirectoryAndPrefix]
      Page<Blob> blobs =
          storage.list(
              bucketName, BlobListOption.currentDirectory(), BlobListOption.prefix(directory));
      for (Blob blob : blobs.iterateAll()) {
        // do something with the blob
      }
      // [END listBlobsWithDirectoryAndPrefix]
      return blobs;
    }
docs: [VARIABLE "my_directory/"]