How to monitor the number of open sessions in Bastion?

Q: How can I see how many sessions are currently going through a Bastion?
A: In the Bastion log you can find a record stating the amount of open sessions every time a session ends or is created.
Below are examples of how the message would look in the log.
When a session ends:   "Session Id: 255 Ended. Open sessions: 4"
When a session has been created:    "Session Id: 258 Created. Open sessions: 3"