As revealed by
QTBUG-95950, some cases are not covered and need to be tested to prevent future regressions.
The various cases are:
- The cache is empty (already tested)
- The cache is not empty, and the currently inserted entry would be the new last-to-expire node in the cache (called "newest")
- The cache has at least two elements and the currently inserted entry is set to expire between the two.
- The cache is not empty, and the currently inserted entry is the new next-to-expire node in the cache (called "oldest")