int newValue = Math.max(0, oldValue - occurrences);
        if (existingCounter.compareAndSet(oldValue, newValue)) {
          if (newValue == 0) {
            // Just CASed to 0; remove the entry to clean up the map. If the removal fails,
            // another thread has already replaced it with a new counter, which is fine.
            countMap.remove(element, existingCounter);
          }
          return oldValue;

        int newValue = Math.max(0, oldValue - occurrences);
        if (existingCounter.compareAndSet(oldValue, newValue)) {
          if (newValue == 0) {
            // Just CASed to 0; remove the entry to clean up the map. If the removal fails,
            // another thread has already replaced it with a new counter, which is fine.
            countMap.remove(element, existingCounter);
          }
          return oldValue;