code: public function validatePlugin($plugin) {
          if ($plugin instanceof Storage\StorageInterface) {
              return;
          }
  
          throw new Storage\Exception\RuntimeException(sprintf('Plugin of type %s is invalid; must implement %s\Storage\StorageInterfaceInterface', (is_object($plugin) ? get_class($plugin) : gettype($plugin)), __NAMESPACE__));
      }
docs: Validate the plugin
  
  Checks that the adapter loaded is an instance
  of Storage\StorageInterfaceInterface.
  
  @param  mixed $plugin
  @return void
  @throws Exception\RuntimeException if invalid