syntax_data: {"ast_node_type":"other","tokens":[{"end":36,"kind":"keyword","start":0,"text":"match"}]}
source_snippet:         match (a.kind(), b.kind()) {
context_before:     ) -> RelateResult<'tcx, ty::GenericArg<'tcx>> {
context_after:             (ty::GenericArgKind::Lifetime(a_lt), ty::GenericArgKind::Lifetime(b_lt)) => {