{"ast_node_type":"other","tokens":[{"end":90,"kind":"keyword","start":0,"text":"///"}]}
/// able to convert between these, as much as they'll be converted back into `DiagMessage`
/// subdiagnostic derive refers to typed identifiers that are `DiagMessage`s, so need to be
/// using `with_subdiagnostic_message` eventually. Don't use this other than for the derive.