/**
  * @param FormMapper $formMapper
  *
  * @return FormBuilder
  */
 protected function getMediaBuilder(FormMapper $formMapper)
 {
     // simulate an association ...
     $fieldDescription = $this->getMediaAdmin()->getModelManager()->getNewFieldDescriptionInstance($this->mediaAdmin->getClass(), 'media', array('translation_domain' => 'SonataMediaBundle'));
     $fieldDescription->setAssociationAdmin($this->getMediaAdmin());
     $fieldDescription->setAdmin($formMapper->getAdmin());
     $fieldDescription->setOption('edit', 'list');
     $fieldDescription->setAssociationMapping(array('fieldName' => 'media', 'type' => ClassMetadataInfo::MANY_TO_ONE));
     return $formMapper->create('mediaId', 'sonata_type_model_list', array('sonata_field_description' => $fieldDescription, 'class' => $this->getMediaAdmin()->getClass(), 'model_manager' => $this->getMediaAdmin()->getModelManager(), 'label' => 'form.label_media'));
 }