{"ast_node_type":"other","tokens":[{"end":49,"kind":"keyword","start":0,"text":"LangItem::FnMut"}]}
        LangItem::FnMut => WellKnownTrait::FnMut,
        LangItem::Fn => WellKnownTrait::Fn,
        LangItem::FnOnce => WellKnownTrait::FnOnce,