{"ast_node_type":"variable","tokens":[{"end":80,"kind":"keyword","start":0,"text":"let"}]}
        let Some(hir::FnDecl { output: hir::FnRetTy::Return(hir_output), .. }) =
        let hir_id = self.local_def_id_to_hir_id(scope_def_id);
            self.hir_fn_decl_by_hir_id(hir_id)