This thread is a good example. The OP showed code exactly as I wrote it, the same way we were shown thus far in the course. It was not correct. Only thru the knowledge of this reply did I figure out that the course was looking for an answer written in a way that was not yet taught.
Edit: in reading this link again, I’m even more sure that there are assumptions being made. “preferring return expressions over literals” is never made clear or even explained in a lesson, however in the exercise in this topic the statement
" * If so, return True if the max_size is greater than self.get_size()"
the course explicitly TELLS us to return a boolean, and then looks for a returned expression.