code: @Override
      protected void channelRead0(ChannelHandlerContext ctx, FullBinaryMemcacheResponse msg) throws Exception {
          if (msg.getOpcode() == SASL_LIST_MECHS_OPCODE) {
              handleListMechsResponse(ctx, msg);
          } else if (msg.getOpcode() == SASL_AUTH_OPCODE) {
              handleAuthResponse(ctx, msg);
          } else if (msg.getOpcode() == SASL_STEP_OPCODE) {
              checkIsAuthed(msg);
          }
      }
docs: Dispatches incoming SASL responses to the appropriate handler methods.
  
  @param ctx the handler context.
  @param msg the incoming message to investigate.
  @throws Exception if something goes wrong during negotiation.