code: def make_big_empty_files(self):
          
          for file_url in self.file_urls:
              local_path = file_url.get_local_path(self.dest_directory)
              with open(local_path, "wb") as outfile:
                  if file_url.size > 0:
                      outfile.seek(int(file_url.size) - 1)
                      outfile.write(b'\0')
docs: Write out a empty file so the workers can seek to where they should write and write their data.