private function store_links(&$file, $hub, $self) {
		if (isset($file->headers['link']['hub']) ||
			  (isset($file->headers['link']) &&
			   preg_match('/rel=hub/', $file->headers['link'])))
		{
			return;
		}

		if ($hub)
		{
			if (isset($file->headers['link']))
			{
				if ($file->headers['link'] !== '')
				{
					$file->headers['link'] = ', ';
				}
			}
			else
			{
				$file->headers['link'] = '';
			}
			$file->headers['link'] .= '<'.$hub.'>; rel=hub';
			if ($self)
			{
				$file->headers['link'] .= ', <'.$self.'>; rel=self';
			}
		}
	}