ArrayFlatterator::getFlattenFields

private function getFlattenFields(array $fields, string $prefix): array
{
	$result = [];

	foreach ($fields as $name => $value)
	{
		$key = "{$prefix}[{$name}]";
		if (is_array($value))
		{
			array_push($result, ...$this->getFlattenFields($value, $key));
		}
		else
		{
			$result[$key] = $value;
		}
	}

	return $result;
}