public function get_hash($key = 0)
	{
		$hashes = $this->get_hashes();
		if (isset($hashes[$key]))
		{
			return $hashes[$key];
		}

		return null;
	}
public function get_hash($key = 0)
	{
		$hashes = $this->get_hashes();
		if (isset($hashes[$key]))
		{
			return $hashes[$key];
		}

		return null;
	}
public function get_hash ( $ key = 0 ) { $ hashes = $ this -> get_hashes ( ) ; if ( isset ( $ hashes [ $ key ] ) ) { return $ hashes [ $ key ] ; } return null ; }
Get a single hash

@link http://www.rssboard.org/media-rss#media-hash
@param int $key
@return string|null Hash as per `media:hash`, prefixed with "$algo:"
Get a single hash