syntax_data: {"ast_node_type":"variable","tokens":[{"end":63,"kind":"keyword","start":0,"text":"if"}]}
source_snippet:         if let Usefulness::Redundant(explanation) = is_useful {
context_before:     for (arm, is_useful) in report.arm_usefulness.iter() {
context_after:             let hir_id = arm.arm_data;