private function replaceTokens(array $originalTokens, array $replacements)
    {
        $tokens = [];
        foreach ($originalTokens as $key => $token) {
            if (! array_key_exists($key, $replacements)) {
                $tokens[] = $token;
                continue;
            }

            foreach ($replacements[$key] as $replacementToken) {
                $tokens[] = $replacementToken;
            }
        }
        return $tokens;
    }