$viewerUrl = preg_replace( $pattern, $viewer, $url );
$headSHA1 = $this->getHeadSHA1();
$replacements = array(
'%h' => substr( $headSHA1, 0, 7 ),
$viewerUrl = preg_replace( $pattern, $viewer, $url );
$headSHA1 = $this->getHeadSHA1();
$replacements = array(
'%h' => substr( $headSHA1, 0, 7 ),