{"ast_node_type":"other","tokens":[{"end":91,"kind":"keyword","start":0,"text":"///"}]}
    /// ExternCrateId being None implies it being imported from the general prelude import.
    /// this contains all kinds of macro, not just `macro_rules!` macro.
    macro_use_prelude: FxHashMap<Name, (MacroId, Option<ExternCrateId>)>,