code: public ChunksManifest write(String spaceId,
                                  ChunkableContent chunkable,
                                  Map<String, String> contentProperties)
          throws NotFoundException {
          for (ChunkInputStream chunk : chunkable) {
              writeSingle(spaceId, null, chunk, null);
          }
  
          ChunksManifest manifest = chunkable.finalizeManifest();
          KnownLengthInputStream manifestStream = manifest.getBody();
  
          AddContentResult result =
              writeContent(spaceId,
                           manifest.getManifestId(),
                           manifestStream,
                           manifestStream.getLength(),
                           contentProperties);
          result.setMd5("md5-not-collected-for-manifest");
  
          return manifest;
      }
docs: This method implements the ContentWriter interface for writing content
  to a DataStore. In this case, the DataStore is a local filesystem.
  The arg spaceId is the path to the destination directory.
  
  @param spaceId           destination where arg chunkable content will be written
  @param contentProperties user defined properties to be associated with content.
  @param chunkable         content to be written