[ [ 'label' => 'Collapsible Group Item #1', 'content' => [ 'test content1', 'test content2' ], ], [ 'label' => 'Collapsible Group Item #2', 'content' => 'Das ist das Haus vom Nikolaus', 'contentOptions' => [ 'class' => 'testContentOptions' ], 'options' => [ 'class' => 'testClass', 'id' => 'testId' ], 'footer' => 'Footer' ], [ 'label' => '