code: public function prepend(ContainerBuilder $container, array $config)
      {
          if (false === array_key_exists($this->getName(), $config)) {
              return;
          }
  
          foreach ($config[$this->getName()] as $id => $section) {
              if (true === $section['create_decrypter']) {
                  $values = $section;
                  unset($values['create_decrypter']);
                  $config['decrypters'] = array_merge(
                      array_key_exists('decrypters', $config) ? $config['decrypters'] : [],
                      [$id => $values]
                  );
              }
          }
  
          return $config;
      }
docs: {@inheritdoc}