$hub_mode = Strings::escapeTags(trim(defaults($_GET, 'hub_mode', '')));
$hub_topic = Strings::escapeTags(trim(defaults($_GET, 'hub_topic', '')));
$hub_challenge = Strings::escapeTags(trim(defaults($_GET, 'hub_challenge', '')));
$hub_mode = Strings::escapeTags(trim(defaults($_GET, 'hub_mode', '')));
$hub_topic = Strings::escapeTags(trim(defaults($_GET, 'hub_topic', '')));
$hub_challenge = Strings::escapeTags(trim(defaults($_GET, 'hub_challenge', '')));