eZ\Publish\Core\Persistence\Legacy\Content\Type\Handler::loadGroup PHP Method

    public function loadGroup($groupId)
    {
        $groups = $this->mapper->extractGroupsFromRows($this->contentTypeGateway->loadGroupData($groupId));
        if (count($groups) !== 1) {
            throw new Exception\TypeGroupNotFound($groupId);
        }
        return $groups[0];
    }