/guava/guava/src/com/google/common/collect/ConcurrentHashMultiset.java
countMap.putIfAbsent( element, newCounter) ;
countMap.remove ( element, existingCounter ) ;
return (countMap.putIfAbsent(element, newCounter) == null) || countMap.replace(element, existingCounter, newCounter); } } else { if (existingCounter.compareAndSet(oldValue, newCount)) { if (newCount == 0) { <extra_id_0> } return true; } } } return false;