protected function getNormalizedNumbers($args)
{
$unit = null;
$originalUnit = null;
$numbers = [];
foreach ($args as $key => $item) {
if ($item[0] !== Type::T_NUMBER) {
$this->throwError('%s is not a number', $item[0]);
break;
}
$number = $item->normalize();
if (null === $unit) {
$unit = $number[2];
$originalUnit = $item->unitStr();
} elseif ($unit !== $number[2]) {
$this->throwError('Incompatible units: "%s" and "%s".', $originalUnit, $item->unitStr());
break;
}
$numbers[$key] = $number;
}
return $numbers;
}