code: static public function round($amount, $currency)
      {
          $precision = static::getPrecision($currency);
          $roundingIncrement = static::getRoundingIncrement($currency);
  
          $amount = round($amount, $precision, \PHP_ROUND_HALF_EVEN);
  
          if (0 < $roundingIncrement && 0 < $precision) {
              $roundingFactor = $roundingIncrement / pow(10, $precision);
              $amount = round($amount / $roundingFactor) * $roundingFactor;
          }
  
          return $amount;
      }
docs: Rounds the amount to currency's precision.
  
  @param float  $amount
  @param string $currency
  
  @return float
  
  @see \Symfony\Component\Intl\NumberFormatter\NumberFormatter::roundCurrency()