In places where a ConcurrentHashMap was used as a set by wrapping it with Collections.newSetFromMap, switch to just using the set returned by ConcurrentHashMap.newKeySet directly. Closes gh-32294
In places where a ConcurrentHashMap was used as a set by wrapping it with Collections.newSetFromMap, switch to just using the set returned by ConcurrentHashMap.newKeySet directly. Closes gh-32294