private byte[] getStitchRequestBody(List<String> signedChunkIds) {
    return StitchRequestSerDe.toJson(signedChunkIds).toString().getBytes(StandardCharsets.UTF_8);
  }
@param signedChunkIds the list of signed chunk IDs to include in the JSON body.
@return a valid JSON body for a stitch request, encoded as UTF-8.
ambry-frontend/src/test/java/com/github/ambry/frontend/NamedBlobPutHandlerTest.java