Example on session timeouts

Write an example demonstrating how to use the `wait_timeout` session variable to modify session timeout:

```
conn.query("SET SESSION wait_timeout = 3600");
```

Locate the repository's documentation or example entry point for MySQL session variables and start by reviewing nearby examples. Add an example showing how to use the wait_timeout session variable to modify the session timeout, then verify that the documented usage matches the issue's conn.query example.

Written by the indexing model from the issue text.