Check::isCorrectSum

private function isCorrectSum($data)
{
	$eps = 0.00001;

	$productSum = 0;
	if (!empty($data['PRODUCTS']))
	{
		foreach ($data['PRODUCTS'] as $item)
			$productSum += $item['SUM'];
	}

	if (!empty($data['DELIVERY']))
	{
		foreach ($data['DELIVERY'] as $delivery)
		{
			$productSum += $delivery['PRICE'];
		}
	}

	$paymentSum = 0;
	if (!empty($data['PAYMENTS']))
	{
		foreach ($data['PAYMENTS'] as $payment)
		{
			$paymentSum += $payment['SUM'];
		}
	}

	return abs($productSum - $paymentSum) < $eps;
}