fn get_cache() -> PANOCCache {
    let nu = icasadi::num_decision_variables();
    let panoc_cache: PANOCCache = PANOCCache::new(
        NonZeroUsize::new(nu).unwrap(),
        TOLERANCE,
        NonZeroUsize::new(LBFGS_MEMORY).unwrap(),
    );
    panoc_cache
}

