return true;
    }

    // value changed
    return false;
  }

  /**
   * Atomically remove {@code key} from the map iff its associated value is 0.
   *
   * @since 20.0
   */
  @CanIgnoreReturnValue
  public boolean removeIfZero(K key) {
    return remove(key, 0);
  }

  /**