public function getField(string $fieldId, bool $tryCaseInsensitive = false)
    {
        if (isset($this->fields[$fieldId])) {
            return $this->fields[$fieldId];
        }

        if ($tryCaseInsensitive) {
            foreach ($this->fields as $name => $field) {
                if (\mb_strtolower($name) === \mb_strtolower($fieldId)) {
                    return $field;
                }
            }
        }

        return null;
    }