syntax_data: {"ast_node_type":"other","tokens":[{"end":77,"kind":"keyword","start":0,"text":"//"}]}
source_snippet:         // knowing ahead of time whether the entire path will succeed or not.
context_before:         // HACK(eddyb) this bypasses `path_append`'s prefix printing to avoid
context_after:         // To support printers that do not implement `PrettyPrinter`, a `Vec` or