A type of widget that can wrap another widget, hiding the wrapped widget's methods. When added to a panel, a composite behaves exactly as if the widget it wraps had been added.
The composite is useful for creating a single widget out of an aggregate of multiple other widgets contained in a single panel.
Example
{@example com.google.gwt.examples.CompositeExample} TODO(rdcastro): Remove the final qualifier from IsRenderable overrides.