One morning shortly before the end of the school year, we arrived at Jane's classroom a bit early.  No one else was there yet, and the classroom door was closed.

Jane anxiously peered in through the window, confirming that the lights were off and the room was empty.  As she walked toward her cubby to hang up her backpack, I heard her mutter, "And now I have proof that teachers don't sleep in their classrooms."

So, that's been cleared up.