{"ast_node_type":"other","tokens":[{"end":67,"kind":"keyword","start":0,"text":"self.tcx.dcx().emit_err(FeaturePreviouslyDeclared"}]}
                self.tcx.dcx().emit_err(FeaturePreviouslyDeclared {
            (FeatureStability::Unstable { .. }, Some((FeatureStability::AcceptedSince(_), _))) => {
                    span,