Troubleshoot the PubSub system

There are several ways to verify that the PubSub system is working correctly:

1. Review the logs, which may contain messages describing the current PubSub system state.

2. Use the subscriber tools to observe the values of subscribed topics as they change.

3. Use the publisher tools to publish test values to topics.

4. Use the browser tool to explore the available topics and data attributes for the RealTime database (RTDB).

The subscriber and publisher tools are typically used together to verify end-to-end PubSub operations.