@Override
  public ByteBuffer processCommand(RequestReader request, Protocol protocol, Cache cache) {
    if (protocol == Protocol.ASCII) {
      return asciiCharset.encode(Reply.OK.toString());
    }
    request.getRequest().position(HEADER_LENGTH);
    return isQuiet() ? null : request.getResponse();
  }
This command is currently no-op

"quit" is a command with no arguments: quit\r\n<br>
<br>

Upon receiving this command, the server closes the connection. However, the client may also
simply close the connection when it no longer needs it, without issuing this command.
geode-memcached/src/main/java/org/apache/geode/internal/memcached/commands/QuitCommand.java