public BlockingTaskExecutorBuilder keepAliveTime(Duration keepAliveTime) {
        checkArgument(!requireNonNull(keepAliveTime, "keepAliveTime").isNegative(),
                      "keepAliveTime: %s (expected: >= 0)", keepAliveTime);
        return keepAliveTimeMillis(keepAliveTime.toMillis());
    }
Sets the amount of keep alive time in seconds.
core/src/main/java/com/linecorp/armeria/common/util/BlockingTaskExecutorBuilder.java