{"ast_node_type":"other","tokens":[{"end":82,"kind":"keyword","start":0,"text":"\"ImplSourceUserDefinedData(impl_def_id={:?},"}]}
            "ImplSourceUserDefinedData(impl_def_id={:?}, args={:?}, nested={:?})",
            f,
            self.impl_def_id, self.args, self.nested