public function changeOwner( $userName, $recursive = FALSE )
	{
		if( !$userName )
			throw new InvalidArgumentException( 'User missing' );
		$number	= (int) chown( $this->folderName, $userName );

		if( !$recursive )
			return $number;
		$iterator = new RecursiveIteratorIterator(
			new RecursiveDirectoryIterator( $this->folderName ),
			RecursiveIteratorIterator::SELF_FIRST
		);
		foreach( $iterator as $item )
			$number += (int) chown( $item, $userName );
		return $number;
	}