How many iterations are made with Create ML?

If you’re classifying images with Create ML and do not specify a maximum number of iterations, I understand it will iterate until it finds an optimal solution. But if it never does, how many iterations will be made before it stops, at a max? Does it stop when the accuracies stop improving? If they continue to improve even slightly at what point will it say there’s been too many iterations and stop? I’m currently at 16, wondering it if could go to 25 or what I should expect.