code: protected function execute(InputInterface $input, OutputInterface $output)
      {
          $parameter = $input->getArgument('parameter');
          $set = $input->getOption('set');
  
          /** @var PairStorage $pairStorage */
          $pairStorage = $this->getContainer()->get('ongr_connections.pair_storage');
  
          if (isset($parameter) & !empty($parameter)) {
              $setValue = $pairStorage->get($parameter);
  
              $output->writeln(
                  "Parameter `$parameter`: " .
                  ($setValue === null ? 'has no value.' : var_export($setValue, true))
              );
  
              if ($set) {
                  $pairStorage->set($parameter, $set);
                  $output->writeln('New value written: ' . var_export($set, true));
              } else {
                  $output->writeln('If you want to write new value, use --set="<new value>" option.');
              }
          }
      }
docs: {@inheritdoc}