{"ast_node_type":"variable","tokens":[{"end":26,"kind":"keyword","start":0,"text":"let"}]}
        let parent_subst =
    pub fn subst_for_coroutine(db: &dyn HirDatabase, parent: DefWithBodyId) -> TyBuilder<()> {
            parent.as_generic_def_id(db).map(|p| generics(db, p).placeholder_subst(db));