Class hierarchy: PlainExpandablePanel ExpandablePanel component in the Plain reference design system ExpandablePanel Region that expands/collapses in place with an animated transition Built with OpenCloseMixin • EffectMixin • TransitionEffectMixin ReactiveElement General-purpose base for writing components in functional-reactive style Built with AttributeMarshallingMixin • ReactiveMixin • ShadowTemplateMixin HTMLElement Standard browser class for all custom elements
