---
    auto_fieldset: 1
    elements:
        - type: Select
          name: select
          label: a Select with optgroups
          options:
            - group: [[1, one], [2, two]]
              label: opt1
            - [3, non-optgroup]
            - group: [[4, four], [5, five]]
              label: opt2
        - type: ComboBox
          name: combo
          label: a ComboBox with optgroups
          values:
              - yes
              - no