{"ast_node_type":"other","tokens":[{"end":87,"kind":"keyword","start":0,"text":"Ok(Some(traits::ImplSource::UserDefined(impl_source)))"}]}
                            Ok(Some(traits::ImplSource::UserDefined(impl_source))) => {
                        match SelectionContext::new(self).select(&obligation) {
                                Some(impl_source.impl_def_id)