There was a steam engine in Prague's main station about seven hours ago. Anyone know why?

This YouTube channel streams Prague's largest train station 24/7:

https://www.youtube.com/watch?v=tmlE1ct0cYk

At about 22:09:30 Wednesday night, a steam engine pulls up to a platform. At about 22:30 it leaves, pulling three cars. No tender, I think.

As with most streams, you can rewind 12 hours. So as of this posting, you have about 5 hours to rewind and watch it if you want. Just very cool to see a steam engine pulling out of a building that is about 120 years old.

edit to add: I would love to be waiting for my commuter train back home after work, and have a steam engine pull up across the platform. I just can't imagine.