@ DocumentNode (location: (1:0)-(1:11))
└── children: (1 item)
    └── @ HTMLDoctypeNode (location: (1:0)-(1:11))
        ├── tag_opening: "<!DOCTYPE" (location: (1:0)-(1:9))
        ├── children: (1 item)
        │   └── @ LiteralNode (location: (1:9)-(1:10))
        │       └── content: " "
        │
        └── tag_closing: ">" (location: (1:10)-(1:11))