bootstrap\Collapse $items

List of groups in the collapse widget. Each array element represents a single group with the following structure:

• label: string, required, the group header label.
• encode: boolean, optional, whether this label should be HTML-encoded. This param will override global $this->encodeLabels param.
• content: array|string|object, required, the content (HTML) of the group
• options: array, optional, the HTML attributes of the group
• contentOptions: optional, the HTML attributes of the group's content