{"ast_node_type":"other","tokens":[{"end":44,"kind":"keyword","start":0,"text":"eager_callback:"}]}
        eager_callback: EagerCallBackFn<'_>,
        resolver: impl Fn(&ModPath) -> Option<MacroId>,
    ) -> Result<ExpandResult<Option<(Mark, Option<Parse<T>>)>>, UnresolvedMacro> {