Async(sharedState: any, _, __: void): Promise&lt;string&gt; {
    console.log(`Order ${sharedState.orderId} processed for ${sharedState.customer}`);
    return DEFAULT_ACTION;
  }
}

// Define NotificationNode
class NotificationNode extends BaseNode {
  public async prepAsync(sharedState: any): Promise&lt;void&gt; {
    // Prepare notification data
  }

  public async execAsync(_: void): Promise&lt;void&gt; {
    // Execute notification logic
  }

  public async postAsync(sharedState: any, _, __: void): Pro