android/guava/src/com/google/common/collect/ConcurrentHashMultiset.java
@Override
  public int count(@NullableDecl Object element) {
    AtomicInteger existingCounter = Maps.safeGet(countMap, element);
    return (existingCounter == null) ? 0 : existingCounter.get();
  }
@Override
  public int count(@NullableDecl Object element) {
    AtomicInteger existingCounter = Maps.safeGet(countMap, element);
    return (existingCounter == null) ? 0 : existingCounter.get();
  }
Returns the number of occurrences of {@code element} in this multiset.

@param element the element to look for
@return the nonnegative number of occurrences of the element