CTaskListState::getInstance

static function getInstance($userId, int $groupId = 0)
{
	CTaskAssert::assertLaxIntegers($userId);
	CTaskAssert::assert($userId > 0);

	$key = $userId .'_'. $groupId;
	if ($groupId)
	{
		$key .= '_'.$groupId;
	}

	if (!array_key_exists($key, self::$instancesOfSelf))
	{
		self::$instancesOfSelf[$key] = new self($userId, $groupId);
	}

	return (self::$instancesOfSelf[$key]);
}