Do opposing trainers have a set number of items they can use? As in, they only have 5 full restores, and if they use all of them on their first Pokemon, they can't use anymore, or is it, let's say, 2 per Pokemon?

For example, I'm fighting Wallace right now, and he used 3 full restores on Whiscash and 2 on Tentacruel. Is there a limit for the number they can use, or is it unlimited?