code: @Override
      public void accumulateChunk(NDArrayMessageChunk chunk) {
          String id = chunk.getId();
          if (!chunks.containsKey(id)) {
              List<NDArrayMessageChunk> list = new ArrayList<>();
              list.add(chunk);
              chunks.put(id, list);
          } else {
              List<NDArrayMessageChunk> chunkList = chunks.get(id);
              chunkList.add(chunk);
          }
  
          log.debug("Accumulating chunk for id " + chunk.getId());
  
  
      }
docs: Accumulate chunks in a map
  until all chunks have been accumulated.
  You can check all chunks are present with
  {@link ChunkAccumulator#allPresent(String)}
  where the parameter is the id
  After all chunks have been accumulated
  you can call {@link ChunkAccumulator#reassemble(String)}
  where the id is the id of the chunk.
  @param chunk the chunk