{"ast_node_type":"other","tokens":[{"end":9,"kind":"keyword","start":0,"text":"where"}]}
    where
    pub fn parallel_prime_caches<F>(&self, num_worker_threads: usize, cb: F) -> Cancellable<()>
        F: Fn(ParallelPrimeCachesProgress) + Sync + std::panic::UnwindSafe,