Botframework v4 preserve dialogSet after deployment

I'm using Microsoft bot framework v4. Its DialogSet is always kept in memory, and will vanish after a code rebuild (i.e deployment), so existing conversation that happens to be in a dialog just before the rebuild, will get an error after deployment is done (the needed dialog is not found).

export class DialogBot extends ActivityHandler {


  private readonly conversationState: BotState;
  private readonly userState: BotState;
  private readonly dialogState: StatePropertyAccessor<DialogState>;
  private readonly nlpProcessor: NlpProcessor;
  private readonly dialogSet: DialogSet;
  private readonly cacheService: CacheService;
  private readonly mainProcessor: MainProcessors;

  constructor(conversationState: BotState, userState: BotState) {
    super();
    this.conversationState = conversationState;
    this.userState = userState;
    this.dialogState = this.conversationState.createProperty<DialogState>(
      'DialogState'
    );
    this.dialogSet = new DialogSet(this.dialogState);

You can see the dialogSet is always initiated new after a deployment

this.dialogSet = new DialogSet(this.dialogState);

Although the dialogStack is persisted into dialogState, its dialogs array isn't

export class DialogSet {
    private readonly dialogs: { [id: string]: Dialog } = {};
    private readonly dialogState: StatePropertyAccessor<DialogState>;
    private _telemetryClient: BotTelemetryClient;
    private _version: string;

The dialogs array only lives in memory, which holds respective Dialog objects the stack refers to. Once you rebuild code, it's gone.

I tried to extend DialogSet class, and save its dialogs property to Blob storage, however, Blob is recording only json, and doesnt reconstruct the dialogs array properly (which holds all Dialog objects).

Anyone has a solution to preserve DialogSet state through deployment ? Many thanks in advance.