cases:
  - title: Header with id label
    id: target
    mdast:
      type: root
      children:
        - type: mystTarget
          label: my_ID
        - type: heading
          depth: 1
          children:
            - type: text
              value: My Header
    myst: |-
      (my_ID)=
      # My Header
    html: |-
      <h1 id="my_id">My Header</h1>