protected function getResult()
{
for ($result = $this->accumulator; $result >= 10; $result = Math::crossSum($result)) {
}
$result = 10 - $result;
return (string) $result === $this->getCheckNumber();
}
/**
* @formatter:on
*/
protected function iterationStep()
{
$this->accumulator += Math::crossSum($this->number * $this->getWeight());
}