code: @Override
      public void channelActive(final ChannelHandlerContext ctx) throws Exception {
          this.ctx = ctx;
          ctx.writeAndFlush(new DefaultBinaryMemcacheRequest().setOpcode(SASL_LIST_MECHS_OPCODE));
      }
docs: Once the channel is marked as active, the SASL negotiation is started.
  
  @param ctx the handler context.
  @throws Exception if something goes wrong during negotiation.