protected function addConnectionsSection($rootNode)
    {
        $rootNode
            ->fixXmlConfig('connection')
            ->children()
                ->arrayNode('connections')
                    ->useAttributeAsKey('id')
                    ->prototype('array')
                        //->performNoDeepMerging()
                        ->children()
                            ->scalarNode('class')->defaultValue('Mandango\Connection')->end()
                            ->scalarNode('server')->end()
                            ->scalarNode('database')->end()
                        ->end()
                        ->append($this->addConnectionOptionsNode())
                    ->end()
                ->end()
            ->end()
        ;
    }