is::setStepSize

public function setStepSize($code, $stepSize)
{
	if(!isset($this->stagesByCode[$code]))
		throw new MainSystemException('Unknown stage code passed');

	if(($stepSize = intval($stepSize)) <= 0)
		throw new MainSystemException('Bad step size passed');

	$this->stagesByCode[$code]['STEP_SIZE'] = $stepSize;
}