ConfigFactory::rename

public ConfigFactory::rename($old_name, $new_name)

public function rename($old_name, $new_name) {
  Cache::invalidateTags($this->get($old_name)->getCacheTags());
  $this->storage->rename($old_name, $new_name);

  // Clear out the static cache of any references to the old name.
  foreach ($this->getConfigCacheKeys($old_name) as $old_cache_key) {
    unset($this->cache[$old_cache_key]);
  }

  // Prime the cache and load the configuration with the correct overrides.
  $config = $this->get($new_name);
  $this->eventDispatcher->dispatch(ConfigEvents::RENAME, new ConfigRenameEvent($config, $old_name));
  return $this;
}