@ DocumentNode (location: (1:0)-(1:10))
└── children: (1 item)
    └── @ HTMLDoctypeNode (location: (1:0)-(1:10))
        ├── tag_opening: "<!DOCtype" (location: (1:0)-(1:9))
        ├── children: []
        └── tag_closing: ">" (location: (1:9)-(1:10))