This is what helps me keeping track of my sample solution and what helps me correcting faster:
I created a class called “solution” (in the pictures below: “PR”). Within that class one student called “solution” (make sure you enable edits after submission -> you’ll be able to add alternative solutions over the years!).
I solve all my tests with this student under an alias (michael.lutz.solution@domain).
solution class with one student:
When my class “AA” has finished their three years of secondary school, I delete and create a new one for my new students. However, I will keep my “solution” class forever.