protected function replaceLinesCompleted(array $linesCompleted, array $completedLines, $strategyName)
    {
        // Remove old strategy lines that are now completed.
        $lines = array();
        foreach ($this->invoice[Tag::Customer][Tag::Invoice][Tag::Line] as $key => $line) {
            if (!in_array($key, $linesCompleted)) {
                $lines[] = $line;
            }
        }

        // And merge in the new completed ones.
        foreach ($completedLines as &$completedLine) {
            if ($completedLine[Meta::VatRateSource] === Creator::VatRateSource_Strategy) {
                $completedLine[Meta::VatRateSource] = Completor::VatRateSource_Strategy_Completed;
                $completedLine[Meta::CompletorStrategyUsed] = $strategyName;
            }
        }
        $this->invoice[Tag::Customer][Tag::Invoice][Tag::Line] = array_merge($lines, $completedLines);
    }