syntax_data: {"ast_node_type":"variable","tokens":[{"end":50,"kind":"keyword","start":0,"text":"let"}]}
source_snippet:             let whole_arm_span = if is_match_arm {
context_before:             let arm_span = cx.tcx.hir_span(hir_id);
context_after:                 // If the arm is followed by a comma, extend the span to include it.