syntax_data: {"ast_node_type":"other","tokens":[{"end":89,"kind":"keyword","start":0,"text":"///"}]}
source_snippet: /// model a tree structure (a replacement for a member like `children: Vec<PlaceIndex>`).
context_before: /// Together, `first_child` and `next_sibling` form an intrusive linked list, which is used to
context_after: #[derive(Debug)]