@ DocumentNode (location: (1:0)-(1:15))
└── children: (1 item)
    └── @ HTMLDoctypeNode (location: (1:0)-(1:15))
        ├── tag_opening: "<!DOCTYPE" (location: (1:0)-(1:9))
        ├── children: (1 item)
        │   └── @ LiteralNode (location: (1:9)-(1:14))
        │       └── content: " html"
        │
        └── tag_closing: ">" (location: (1:14)-(1:15))