checkState(newMap instanceof MapMakerInternalMap);
        newMap.putAll(map);
        return newMap;
      }
    },
    MapMakerWeakKeysStrongValues {
      @Override
      public <K extends Comparable<K>, V> Map<K, V> create(Map<K, V> map) {
        ConcurrentMap<K, V> newMap = new MapMaker().weakKeys().makeMap();

 * @author mbechler
 *
 */
public interface Credentials {

    /**
     * Unwrap credentials to a specific type.
     *
     * @param <T> the credential type to unwrap to
     * @param type the class of the credential type to unwrap to
     * @return instance for type, null if the type cannot be unwrapped
     */
    <T extends Credentials> T unwrap(Class<T> type);

    /**
     * Get the domain of the user account.

        verify(tree).send(request, param);
    }

    @Test
    @DisplayName("unwrap and close are available via SmbTree")
    void unwrap_and_close_interactions() {
        // Arrange
        when(tree.unwrap(SmbTreeInternal.class)).thenReturn(tree);

        // Act
        SmbTree unwrapped = tree.unwrap(SmbTreeInternal.class);
        tree.close();

        // Assert
        assertNotNull(unwrapped);

  @Override
  public boolean containsRow(@Nullable Object rowKey) {
    return Maps.safeContainsKey(rowMap(), rowKey);
  }

  @Override
  public boolean containsColumn(@Nullable Object columnKey) {
    return Maps.safeContainsKey(columnMap(), columnKey);
  }

  @Override
  public Set<R> rowKeySet() {
    return rowMap().keySet();
  }

  @Override
  public Set<C> columnKeySet() {
    return columnMap().keySet();

     */
    boolean isStale();

    /**
     * Unwraps this handle to the specified type.
     *
     * @param <T> the type to unwrap to
     * @param type the class of the type to unwrap to
     * @return unwrapped instance
     */
    <T extends SmbPipeHandle> T unwrap(Class<T> type);

        // Act & Assert
        // unwrap to interface itself should return same instance
        CredentialsInternal unwrapped = creds.unwrap(CredentialsInternal.class);
        assertNotNull(unwrapped, "unwrap to CredentialsInternal returns instance");
        assertSame(creds, unwrapped, "unwrap returns the same object instance");

        target = new SmbPipeHandleImpl(pipe);
    }

    @Test
    @DisplayName("unwrap returns self for assignable type; throws for incompatible and null")
    void testUnwrap() {
        // Happy path: unwrap to concrete type
        SmbPipeHandleImpl unwrapped = target.unwrap(SmbPipeHandleImpl.class);
        assertSame(target, unwrapped);

        // Incompatible type: expect ClassCastException

  @Override
  public SortedSet<R> rowKeySet() {
    return (SortedSet<R>) rowMap().keySet();
  }

  /**
   * {@inheritDoc}
   *
   * <p>This method returns a {@link SortedMap}, instead of the {@code Map} specified in the {@link
   * Table} interface.
   */
  @Override
  public SortedMap<R, Map<C, V>> rowMap() {
    return (SortedMap<R, Map<C, V>>) super.rowMap();
  }

  @Override
  SortedMap<R, Map<C, V>> createRowMap() {

    public Set<R> rowKeySet() {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.rowKeySet();
    }

    @Override
    public Map<R, Map<C, V>> rowMap() {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.rowMap();
    }

    private static final long serialVersionUID = 0;
  }

  @Override
  protected Table<String, Integer, Character> create(@Nullable Object... data) {

  }

  @LazyInit private transient @Nullable Map<R, Map<C, V>> rowMap;

  @Override
  public Map<R, Map<C, V>> rowMap() {
    Map<R, Map<C, V>> result = rowMap;
    return (result == null) ? rowMap = createRowMap() : result;
  }

  Map<R, Map<C, V>> createRowMap() {
    return new RowMap();
  }

  @WeakOuter
  class RowMap extends ViewCachingAbstractMap<R, Map<C, V>> {
    @Override