{"ast_node_type":"variable","tokens":[{"end":49,"kind":"keyword","start":0,"text":"let"}]}
    let hir_id = tcx.local_def_id_to_hir_id(def);
    let captures = tcx.mk_captures_from_iter(captures);
    let kind_origin = typeck_results.closure_kind_origins().get(hir_id);