docs: public Task<Void> makeVoid() {
      return this.continueWithTask(new Continuation<TResult, Task<Void>>() {
        @Override
        public Task<Void> then(Task<TResult> task) throws Exception {
          if (task.isCancelled()) {
            return Task.cancelled();
          }
          if (task.isFaulted()) {
            return Task.forError(task.getError());
          }
          return Task.forResult(null);
        }
      });
    }