{"ast_node_type":"variable","tokens":[{"end":60,"kind":"keyword","start":0,"text":"let"}]}
        let method = self.register_infer_ok_obligations(ok);
        let ok = self.try_overloaded_deref(expr.span, oprnd_ty)?;
        if let ty::Ref(_, _, hir::Mutability::Not) = method.sig.inputs()[0].kind() {