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.