docs: async def async_enqueue_multiconvert(self, url_string, to_type):
          '''
          Enqueue a multi-step conversion process, from the given URL string
          (which is assumed to have been downloaded / resolved)
          '''
          worker = self.pick_sticky(url_string)
          args = (url_string, to_type)
          await worker.enqueue(enums.Task.MULTICONVERT, args)