Provides user interface objects that combine two or more look and feels. When a component asks for its UI, this look and feel returns a multiplexing UI that handles all communications with both the default look and feel and one or more auxiliary look and feels. For example, if a user combines an auxiliary audio look and feel with the Motif look and feel, the `JButton.getUI` method would return an instance of `MultiButtonUI`, which would handle both a `MotifButtonUI` and an `AudioButtonUI`.

For more information, see Using the Multiplexing Look and Feel.

Note: Most of the Swing API is not thread safe. For details, see Threads and Swing, a section in The Java Tutorial. @since 1.2 @serial exclude