{"ast_node_type":"other","tokens":[{"end":62,"kind":"keyword","start":0,"text":"associated_ty_id:"}]}
            associated_ty_id: to_assoc_type_id(future_output),
        let future_projection = crate::AliasTy::Projection(crate::ProjectionTy {
            substitution: Substitution::from1(Interner, ret_param_future.clone()),