This was changed earlier that it doesn't return the same mock every time but creates a new mock in findContainer. So the single mock that used to be returned every time is no longer needed.
Contributes to issue CURA-3497.
This test does not test the removing of these files. In general, to make a test run fast, it should not perform any disk operations.
Contributes to issue CURA-3497.
This tests if container stacks, when loading, get implemented with the correct class: Either an extruder stack or a global stack.
Contributes to issue CURA-3497.
