File::output

public function output(WebPackerBuilder $builder)
{
	if (!$this->moduleId)
	{
		throw new SystemException('Module ID is empty.');
	}
	if (!$this->name)
	{
		throw new SystemException('File name is empty.');
	}

	$content = $builder->stringify();
	$id = $this->saveFile($content);

	$result = (new Result())->setId($id)->setContent($content);
	if (!$id)
	{
		$result->addError(new Error('Empty file ID.'));
	}

	return $result;
}