protected function tryVatRate($vatRate)
    {
        $this->description = "ApplySameVatRate($vatRate)";
        $this->replacingLines = array();
        $vatAmount = 0.0;
        foreach ($this->lines2Complete as $line2Complete) {
            $vatAmount += $this->completeLine($line2Complete, $vatRate);
        }

        $this->invoice[Tag::Customer][Tag::Invoice][Meta::CompletorStrategy . $this->getName()] = "tryVatRate($vatRate): $vatAmount";
        // If the vat totals are equal, the strategy worked.
        // We allow for a reasonable margin, as rounding errors may add up.
        return Number::floatsAreEqual($vatAmount, $this->vat2Divide, 0.04);
    }