Group::isExtranetGroup

public function isExtranetGroup()
{
	if ($group = $this->getGroup())
	{
		if (!isset($this->group['IS_EXTRANET']))
		{
			$this->group['IS_EXTRANET'] = false;
			if (BitrixMainLoader::includeModule("extranet"))
			{
				$groupId = (int)$group['ID'];
				$this->group['IS_EXTRANET'] = CExtranet::IsExtranetSocNetGroup($groupId);
			}
		}
	}

	return (bool)$this->group['IS_EXTRANET'];
}