code: private function assertClient(ClientInterface $client)
      {
          if ($client->getConnection() instanceof AggregateConnectionInterface) {
              throw new NotSupportedException(
                  'Cannot initialize a monitor consumer over aggregate connections.'
              );
          }
  
          if ($client->getCommandFactory()->supportsCommand('MONITOR') === false) {
              throw new NotSupportedException("'MONITOR' is not supported by the current command factory.");
          }
      }
docs: Checks if the passed client instance satisfies the required conditions
  needed to initialize a monitor consumer.
  
  @param ClientInterface $client Client instance used by the consumer.
  
  @throws NotSupportedException