我怎样才能让图像在UI PickerView组件中快速出现?

I am trying to use images in a Swift PickerView. I don't know how to get the images to actually appear in the component. I know how to do this using Strings with the titleForRow function but I don't know how to do this using images. Here is my code so far:I am trying to use images in a Swift PickerView