code: public function getConfigTreeBuilder()
      {
          $builder = new TreeBuilder;
          $node = $builder->root('ds_parameter');
          $node
              ->children()
                  ->arrayNode('parameters')
                      ->prototype('array')
                          ->children()
                              ->scalarNode('title')
                              ->end()
                              ->scalarNode('key')
                              ->end()
                              ->booleanNode('encrypt')
                                  ->defaultFalse()
                              ->end()
                          ->end()
                      ->end()
                  ->end()
              ->end();
  
          return $builder;
      }
docs: {@inheritdoc}