docs: public Attachment getAttachment(final String id, final String rev, final String
              attachmentName) {
          try {
              return get(queue.submit(new SQLCallable<Attachment>() {
                  @Override
                  public Attachment call(SQLDatabase db) throws Exception {
                      long sequence = new GetSequenceCallable(id, rev).call(db);
                      return AttachmentManager.getAttachment(db, attachmentsDir,
                              attachmentStreamFactory, sequence, attachmentName);
                  }
              }));
          } catch (ExecutionException e) {
              logger.log(Level.SEVERE, "Failed to get attachment", e);
          }
  
          return null;
      }