Run task in current thread. Handy for testing. How it works: when thread factory returns null, ThreadPoolExecutor invokes CallerRunsPolicy

ExecutorUtils.java

@UtilityClass
public class ExecutorUtils {

    public static ExecutorService currentThreadExecutorService() {
        return new ThreadPoolExecutor(0, 1, 0L, SECONDS, new SynchronousQueue<>(), r -> null, new CallerRunsPolicy());
    }

}