{"ast_node_type":"other","tokens":[{"end":100,"kind":"keyword","start":0,"text":"err.subdiagnostic(errors::DerefImplsIsEmpty"}]}
                    err.subdiagnostic(errors::DerefImplsIsEmpty { span: self.expr_span, deref_ty });
                if deref_ty != self.expr_ty.peel_refs() {
                }