code: public void setChildChannelOptions(final Map<ChannelOption, Object> channelOptions) {
          this.childChannelOptions = channelOptions == null ? Collections.<ChannelOption, Object> emptyMap()
              : channelOptions;
      }
docs: Add child options to the {@link io.netty.bootstrap.ServerBootstrap}.
  
  @param channelOptions the additional child {@link io.netty.channel.ChannelOption}s.
  @see io.netty.bootstrap.ServerBootstrap#childOption(io.netty.channel.ChannelOption, Object)