syntax_data: {"ast_node_type":"variable","tokens":[{"end":20,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:         let report =
context_before:     ) -> Result<UsefulnessReport<'p, 'tcx>, ErrorGuaranteed> {
context_after:             rustc_pattern_analysis::rustc::analyze_match(&cx, &arms, scrut_ty).map_err(|err| {