{"ast_node_type":"other","tokens":[{"end":84,"kind":"keyword","start":0,"text":"TypeError::RegionsInsufficientlyPolymorphic(placeholder.bound,"}]}
        TypeError::RegionsInsufficientlyPolymorphic(placeholder.bound, other_region)
        debug!("error: placeholder={:?}, other_region={:?}", placeholder, other_region);
    }