{"ast_node_type":"other","tokens":[{"end":72,"kind":"keyword","start":0,"text":"impl_def.syntax().descendants().find_map(ast::SelfParam::cast)?;"}]}
        impl_def.syntax().descendants().find_map(ast::SelfParam::cast)?;
    let self_param: ast::SelfParam =
    ted::replace(self_param.syntax(), mut_self_param.clone_for_update().syntax());