protected function parseResponse($body)
    {
        $this->historyCount = (int)$body->getElementsByTagName('historyEntry')->length;

        if ($this->historyCount > 0) {

            for ($i = 0; $i < $this->historyCount; $i++) {

                $this->history[$i] = [];

                $historyEntry = $body->getElementsByTagName('historyEntry')->item($i);

                for ($j = 0; $j < $historyEntry->childNodes->length; $j++) {

                    $name  = $historyEntry->childNodes->item($j)->tagName;
                    $value = $historyEntry->childNodes->item($j)->nodeValue;

                    $this->history[$i][$name] = $value;
                }
            }
        }
    }