private Long createBlob(final InputStream inputStream) {
   Objects.requireNonNull(inputStream, "inputStream cannot be null");
   try (BlobAccessor blobAccessor = blobstore.createBlob()) {
     int nRead;
     byte[] data = new byte[BUFFER_SIZE];
     while ((nRead = inputStream.read(data, 0, data.length)) != -1) {
       blobAccessor.write(data, 0, nRead);
     }
     return blobAccessor.getBlobId();
   } catch (IOException e) {
     throw new UncheckedIOException(e);
   }
 }