code: public function onMergeConfig(ModuleEvent $event)
      {
          $listener = $event->getConfigListener();
          $config = $listener->getMergedConfig(false);
  
          // disable subsplit command if we not in main development
          if (
              isset($config['console'])
              && !$this->isInMainDevelopment()
              && isset($config['console']['router']['routes']['subsplit'])
          ) {
              unset($config['console']['router']['routes']['subsplit']);
          }
  
          $listener->setMergedConfig($config);
      }
docs: Manipulate configuration
  @param ModuleEvent $event