{"ast_node_type":"other","tokens":[{"end":38,"kind":"keyword","start":0,"text":"Some(DerefType::DerefMut)"}]}
        Some(DerefType::DerefMut) => {
        Some(DerefType::Deref) => DerefType::DerefMut,
            cov_mark::hit!(test_add_field_deref_impl_already_exists);