*
   * @return the collection of replaced values, or an empty collection if no values were previously
   *     associated with the key. The collection <i>may</i> be modifiable, but updating it will have
   *     no effect on the multimap.
   */
  @CanIgnoreReturnValue
  Collection<V> replaceValues(@ParametricNullness K key, Iterable<? extends V> values);

  /**

 * worse performance than data access by row key.
 *
 * <p>The methods returning collections or maps always return views of the underlying table.
 * Updating the table can change the contents of those collections, and updating the collections
 * will change the table.
 *
 * <p>All methods that modify the table are optional, and the views returned by the table may or may

   * calling {@code get(columnKey, rowKey)} on the generated table always returns the same value as
   * calling {@code get(rowKey, columnKey)} on the original table. Updating the original table
   * changes the contents of the transposed table and vice versa.
   *
   * <p>The returned table supports update operations as long as the input table supports the

    final Service service;
    // We store the state in a weak reference to ensure that if something went wrong while
    // constructing the ServiceManager we don't pointlessly keep updating the state.
    final WeakReference<ServiceManagerState> state;

    ServiceListener(Service service, WeakReference<ServiceManagerState> state) {
      this.service = service;
      this.state = state;
    }