Calling setRules multiple times possible?

Like this?
https://www.php.net/manual/en/function.array-merge.php

Yes, i did it this way but thougt there was an codeigniter native functionality for the validation rules. With a helper function in my controller i collect all rules and pass it to the setRules method. I think if i call the setRules method twice, the first rules are overwritten and set new by the second call