syntax_data: {"ast_node_type":"other","tokens":[{"end":50,"kind":"keyword","start":0,"text":"explanation:"}]}
source_snippet:     explanation: &RedundancyExplanation<'p, 'tcx>,
context_before:     pat: &DeconstructedPat<'p, 'tcx>,
context_after:     whole_arm_span: Option<Span>,