public static int numCommonBlockingTaskThreads() {
        return NUM_COMMON_BLOCKING_TASK_THREADS;
    }
Returns the default number of {@linkplain CommonPools#blockingTaskExecutor() blocking task executor}
threads. Note that this flag has no effect if a user specified the blocking task executor explicitly
via {@link ServerBuilder#blockingTaskExecutor(ScheduledExecutorService, boolean)}.

<p>The default value of this flag is {@value DefaultFlagsProvider#NUM_COMMON_BLOCKING_TASK_THREADS}.
Specify the {@code -Dcom.linecorp.armeria.numCommonBlockingTaskThreads=<integer>} JVM option
to override the default value.
core/src/main/java/com/linecorp/armeria/common/Flags.java