@ DocumentNode (location: (1:0)-(1:30))
└── children: (2 items)
    ├── @ 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))
    │
    └── @ HTMLDoctypeNode (location: (1:15)-(1:30))
        ├── tag_opening: "<!DOCTYPE" (location: (1:15)-(1:24))
        ├── children: (1 item)
        │   └── @ LiteralNode (location: (1:24)-(1:29))
        │       └── content: " html"
        │
        └── tag_closing: ">" (location: (1:29)-(1:30))