public function configureDatagridFilters(DatagridMapper $filter)
{
$filter->add('name')->add('sku')->add('enabled')->add('productCategories.category', null, array('field_options' => array('expanded' => false, 'multiple' => true)))->add('productCollections.collection', null, array('field_options' => array('expanded' => false, 'multiple' => true)));
}