docs: public void enqueue(@Nullable final Callback<T> callback) {
      checkIfExecuted();
      this.callback.set(callback);
      dispatcher.execute(new Runnable() {
        @Override public void run() {
          T result;
          try {
            result = perform();
          } catch (Exception e) {
            notifyFailure(new ApolloException("Failed to perform store operation", e));
            return;
          }
  
          notifySuccess(result);
        }
      });
    }