code: public EtcdNettyConfig setEventLoopGroup(EventLoopGroup eventLoopGroup, boolean managed) {
      if (this.eventLoopGroup != null && this.managedEventLoopGroup) { // if i manage it, close the old when new one come
        this.eventLoopGroup.shutdownGracefully();
      }
      this.eventLoopGroup = eventLoopGroup;
      this.managedEventLoopGroup = managed;
      return this;
    }
docs: Set a custom event loop group. For use within existing netty architectures
  
  @param eventLoopGroup eventLoopGroup to set.
  @param managed whether event loop group will be closed when etcd client close, true represent yes
  @return itself for chaining.