static BlockingTaskExecutor of() {
        return CommonPools.blockingTaskExecutor();
    }
Returns the default {@link BlockingTaskExecutor} with a 60s timeout and unbounded work
queue. Note that this method returns the same instance with what
{@link CommonPools#blockingTaskExecutor()} returns.
core/src/main/java/com/linecorp/armeria/common/util/BlockingTaskExecutor.java