Download Dialog 'File Already Exists'

I'm doing some automated testing that requires a file to be downloaded and then the same file re-uploaded, but for the sake of server space, it would be silly for each downloaded file to have a different name and have a plethora of the same file.  Sadly, I don't know how I would go about handling the "File Already Exists" alert that pops up in the File Explorer when saving the document.

Thanks