src/main/java/io/reactivex/schedulers/Schedulers.java
public static void shutdown() {
        computation().shutdown();
        io().shutdown();
        newThread().shutdown();
        single().shutdown();
        trampoline().shutdown();
        SchedulerPoolFactory.shutdown();
    }
public static void shutdown() {
        computation().shutdown();
        io().shutdown();
        newThread().shutdown();
        single().shutdown();
        trampoline().shutdown();
        SchedulerPoolFactory.shutdown();
    }
Shuts down the standard Schedulers.
<p>The operation is idempotent and thread-safe.