syntax_data: {"ast_node_type":"function","tokens":[{"end":78,"kind":"keyword","start":0,"text":"fn"}]}
source_snippet:     fn into_diag(self, dcx: DiagCtxtHandle<'a>, level: Level) -> Diag<'a, G> {
context_before: impl<'a, G: EmissionGuarantee> Diagnostic<'a, G> for NonExhaustivePatternsTypeNotEmpty<'_, '_, '_> {
context_after:         let mut diag =