{"ast_node_type":"variable","tokens":[{"end":92,"kind":"keyword","start":0,"text":"let"}]}
        let vid = self.inner.borrow_mut().type_variables().new_var(self.universe(), origin);
    pub fn next_ty_var_with_origin(&self, origin: TypeVariableOrigin) -> Ty<'tcx> {
        Ty::new_var(self.tcx, vid)