My.Vendor:Document.WithChildren:
  superTypes:
    Neos.Neos:Document: true
  childNodes:
    main:
      label: 'Main content'
      type: Neos.Neos:ContentCollection
      options:
        someCustomOption: true
      constraints:
        nodeTypes:
          Neos.Neos:Content: true
    footer:
      label: ~
      options:
        preset: 'footer'