FluentDOM\Loader\Text\CSV::getHeaders PHP Method

    private function getHeaders(array $line, $hasHeaderLine, $fields = NULL)
    {
        if (is_array($fields)) {
            $headers = [];
            foreach ($line as $index => $field) {
                $key = $hasHeaderLine ? $field : $index;
                $headers[$index] = isset($fields[$key]) ? $fields[$key] : FALSE;
            }
            return $headers;
        } elseif ($hasHeaderLine) {
            return $line;
        } else {
            return array_keys($line);
        }
    }