public ClientFactoryBuilder workerGroup(EventLoopGroup workerGroup, boolean shutdownOnClose) {
        option(ClientFactoryOptions.WORKER_GROUP, requireNonNull(workerGroup, "workerGroup"));
        option(ClientFactoryOptions.SHUTDOWN_WORKER_GROUP_ON_CLOSE, shutdownOnClose);
        return this;
    }
Sets the worker {@link EventLoopGroup} which is responsible for performing socket I/O and running
{@link Client#execute(ClientRequestContext, Request)}.
If not set, {@linkplain CommonPools#workerGroup() the common worker group} is used.

@param shutdownOnClose whether to shut down the worker {@link EventLoopGroup}
                       when the {@link ClientFactory} is closed
core/src/main/java/com/linecorp/armeria/client/ClientFactoryBuilder.java