History::__construct

public function __construct(int $entityId, string $entityType)
{
	if (!in_array($entityType, self::AVAILABLE_TYPES, true))
	{
		// todo :err or null
		return;
	}

	$this->entityId = $entityId;
	$this->entityType = $entityType;

	$this->loadStack();
	$this->loadStep();

	if ($this->step > $this->getStackCount())
	{
		$this->saveStep($this->getStackCount());
	}
}