public boolean removeIfZero(K key) {
    return remove(key, 0);
  }

  /**
   * Removes all mappings from this map whose values are zero.
   *
   * <p>This method is not atomic: the map may be visible in intermediate states, where some of the
   * zero values have been removed and others have not.
   */
  public void removeAllZeros() {
    Iterator<Entry<K, AtomicLong>> entryIterator = map.entrySet().iterator();