{"ast_node_type":"other","tokens":[{"end":71,"kind":"keyword","start":0,"text":"hir::ItemKind::Impl(impl_)"}]}
                hir::ItemKind::Impl(impl_) => impl_.of_trait.is_some(),
            let containing_impl_is_for_trait = match &containing_item.kind {
                _ => bug!("parent of an ImplItem must be an Impl"),