LGTM. We should run a differences job to check for performance issues and result changes.

Differences job: https://jenkins.internal.semmle.com/job/Changes/job/Java-Differences/816/

Would it make sense to cover java.lang.reflect.Array as well (given that you included predicates for Arrays)?

Edit: Apparently that is not part of this pull request anymore

Would it make sense to cover java.lang.reflect.Array as well (given that you included predicates for Arrays)?

Edit: Apparently that is not part of this pull request anymore

Apologies, I had accidentally included some unrelated commits on the branch.

Not directly related to the java.util.Collections class, but would it make sense to cover the unmodifiable collection factory methods added in Java 9 & 10 as well? Or should this be a separate GitHub issue?

• List.copyOf(Collection<? extends E>)

• List.of(...) (all overloads except of() which returns an empty list)

• Set.copyOf(Collection<? extends E>)

• Set.of(...) (all overloads except of() which returns an empty set)

• Map.copyOf(Map<? extends K, ? extends V>)

• Map.of(...) (all overloads except of() which returns an empty map)

• Map.ofEntries(Map.Entry<? extends K, ? extends V>...)

Also, the differences job looks fine - a few additional results and no noticeable change in performance.

Not directly related to the java.util.Collections class, but would it make sense to cover the unmodifiable collection factory methods added in Java 9 & 10 as well? Or should this be a separate GitHub issue?

Thanks, I'll make a new PR for those methods.