+ $form[$key]['#attributes']['class'][] = 'form-wrapper--checkboxes';
+ $form[$key]['#attributes']['class'][] = 'form-wrapper--' . str_replace('_', '-', $key);
+ $count = count($form[$key]['#options']);
+ $form[$key]['#attributes']['class'][] = 'form-wrapper--count-' . ($count > 3 ? 'max' : $count);
+