return (frequency == null) ? 0 : frequency;
            }
          };
        }
      };
    }

    @Override
    public Iterator<E> iterator() {
      return Multisets.iteratorImpl(this);
    }

    @Override
    int distinctElements() {
      return backingMap.size();
    }
  }

              return (frequency == null) ? 0 : frequency;
            }
          };
        }
      };
    }

    @Override
    public Iterator<E> iterator() {
      return Multisets.iteratorImpl(this);
    }

    @Override
    int distinctElements() {
      return backingMap.size();
    }
  }

    @Override
    public void clear() {
      multiset().clear();
    }
  }

  /** An implementation of {@link Multiset#iterator}. */
  static <E extends @Nullable Object> Iterator<E> iteratorImpl(Multiset<E> multiset) {
    return new MultisetIteratorImpl<>(multiset, multiset.entrySet().iterator());
  }

  static final class MultisetIteratorImpl<E extends @Nullable Object> implements Iterator<E> {

    @Override
    public void clear() {
      multiset().clear();
    }
  }

  /** An implementation of {@link Multiset#iterator}. */
  static <E extends @Nullable Object> Iterator<E> iteratorImpl(Multiset<E> multiset) {
    return new MultisetIteratorImpl<>(multiset, multiset.entrySet().iterator());
  }

  static final class MultisetIteratorImpl<E extends @Nullable Object> implements Iterator<E> {

        ConcurrentHashMultiset.this.setCount(last.getElement(), 0);
        last = null;
      }
    };
  }

  @Override
  public Iterator<E> iterator() {
    return Multisets.iteratorImpl(this);
  }

  @Override
  public void clear() {
    countMap.clear();
  }

  @WeakOuter
  private class EntrySet extends AbstractMultiset<E>.EntrySet {
    @Override

        node = node.succ()) {
      action.accept(node.getElement(), node.getCount());
    }
  }

  @Override
  public Iterator<E> iterator() {
    return Multisets.iteratorImpl(this);
  }

  @Override
  public SortedMultiset<E> headMultiset(@ParametricNullness E upperBound, BoundType boundType) {
    return new TreeMultiset<>(
        rootReference,

        setCount(prevEntry.getElement(), 0);
        prevEntry = null;
      }
    };
  }

  @Override
  public Iterator<E> iterator() {
    return Multisets.iteratorImpl(this);
  }

  @Override
  public SortedMultiset<E> headMultiset(@ParametricNullness E upperBound, BoundType boundType) {
    return new TreeMultiset<>(
        rootReference,