form:
  tabs:
    - name: tabText
      label: Text
      fields:
        - name: message
          fieldType: switchable
          label: Message
          options:
            - name: plainText
              label: Plain
              selected: true
              value: plainText
            - name: richText
              label: Rich
              value: richText
          fields:
            - name: plainText
              fieldType: text
              label: Plain text message
              rows: 5
            - name: richText
              fieldType: richText
              label: Rich text message
              height: 200