class BagUserState {

  public void append(T t) {
    checkState(
        !isClosed,
        "Bag user state is no longer usable because it is closed for %s",
        request.getStateKey());
    newValues.add(t);
  }

  public  BagUserState(
      BeamFnStateClient beamFnStateClient,
      String instructionId,
      String ptransformId,
      String stateId,
      ByteString encodedWindow,
      ByteString encodedKey,
      Coder<T> valueCoder);

}