private function getDefaultConfiguration(\DOMXPath $xpath)
    {
        $charFilters = $this->parseFilters($xpath, self::CHAR_FILTER_TYPE_ROOT_NODE, self::CHAR_FILTER_TYPE_NODE);
        $filters     = $this->parseFilters($xpath, self::FILTER_TYPE_ROOT_NODE, self::FILTER_TYPE_NODE);
        $analyzers   = $this->parseAnalyzers($xpath, array_keys($charFilters), array_keys($filters));

        $defaultConfiguration = [
            self::CHAR_FILTER_TYPE_NODE => $charFilters,
            self::FILTER_TYPE_NODE      => $filters,
            self::ANALYZER_TYPE_NODE    => $analyzers,
        ];

        return $defaultConfiguration;
    }