/** {@inheritdoc} */
public function process(Metadata $metadata, \Exception $exception = null)
{
$this->callbackExecuted = true;
$metadata->setAppRootDir('app_root_dir');
$metadata->setStage('stage');
$metadata->setAppVersion('app_version');
$metadata->addTags(array('tag1' => 1, 'tag3' => 3));
$metadata->addTag('tag2', 2);
$metadata->removeTag('tag3');
$metadata->addMetadata(array('metadatum1' => 1, 'metadatum3' => 3));
$metadata->addMetadatum('metadatum2', 2);
$metadata->removeMetadatum('metadatum3');
$metadata->addCategories(array('category1', 'category2'));
$metadata->addCategory('category3');
$metadata->removeCategory('category3');
$metadata->addGrouping(array('group1' => 'value1'));
$metadata->groupBy('group1', 'value2');
$metadata->groupBy('group2', 'value2');
}