{"ast_node_type":"import","tokens":[{"end":82,"kind":"keyword","start":0,"text":"use_ctxt:"}]}
        use_ctxt: Span,        // syntax context of the field name at the use site
        hir_id: hir::HirId,    // ID of the field use
        def: ty::AdtDef<'tcx>, // definition of the struct or enum