syntax_data: {"ast_node_type":"other","tokens":[{"end":36,"kind":"keyword","start":0,"text":"unstable_opts:"}]}
source_snippet:     unstable_opts: &UnstableOptions,
context_before:     early_dcx: &EarlyDiagCtxt,
context_after:     (print_name, print_kind): (&str, PrintKind),