code: @SneakyThrows(IOException.class)
      private ByteBuffer copyData(List<ReadResultEntryContents> contents) {
          int totalSize = contents.stream().mapToInt(ReadResultEntryContents::getLength).sum();
  
          ByteBuffer data = ByteBuffer.allocate(totalSize);
          int bytesCopied = 0;
          for (ReadResultEntryContents content : contents) {
              int copied = StreamHelpers.readAll(content.getData(), data.array(), bytesCopied, totalSize - bytesCopied);
              Preconditions.checkState(copied == content.getLength(), "Read fewer bytes than available.");
              bytesCopied += copied;
          }
          return data;
      }
docs: Copy all of the contents provided into a byteBuffer and return it.