- $classes = $this->mCollapsible ? [ 'mw-collapsible' ] : [];
- if ( $this->mCollapsed ) {
- $classes[] = 'mw-collapsed';
- }
- $content = new OOUI\FieldsetLayout( [
+ $phpClass = $this->mCollapsible ? CollapsibleFieldsetLayout::class : OOUI\FieldsetLayout::class;
+ $content = new $phpClass( [