{"ast_node_type":"other","tokens":[{"end":22,"kind":"keyword","start":0,"text":"match"}]}
        match (a, b) {
    fn to_trace(cause: &ObligationCause<'tcx>, a: Self, b: Self) -> TypeTrace<'tcx> {
            (ImplSubject::Trait(trait_ref_a), ImplSubject::Trait(trait_ref_b)) => {