Db::getRepositoryForModel() 

\nn\t3::Db()->getRepositoryForModel($className = NULL); 

Get an instance of the repository for a model (or a model class name).

\nn\t3::Db()->getRepositoryForModel( \My\Domain\Model\Name::class );
\nn\t3::Db()->getRepositoryForModel( $myModel );
Copied!
@param mixed $className
@return \TYPO3\CMS\Extbase\Persistence\Repository

Source Code 

public function getRepositoryForModel( $className = null )
{
	if (!is_string($className)) $className = get_class($className);
	$repositoryName = \TYPO3\CMS\Core\Utility\ClassNamingUtility::translateModelNameToRepositoryName( $className );
	return \nn\t3::injectClass( $repositoryName );
}
Copied!