$builder->setNodeClass('CuStOm', __NAMESPACE__.'\\SomeNodeDefinition');
$node1 = $builder->node('', 'CUSTOM');
$node2 = $builder->node('', 'custom');
$builder->setNodeClass('CuStOm', __NAMESPACE__.'\\SomeNodeDefinition');
$node1 = $builder->node('', 'CUSTOM');
$node2 = $builder->node('', 'custom');