docs: def get_processed_key_name(self):
          """Return the full path to use for the processed file."""
          if not hasattr(self, '_processed_key_name'):
              path, upload_name = os.path.split(self.get_upload_key().name)
              key_name = self._generate_processed_key_name(
                  self.process_to, upload_name)
              self._processed_key_name = os.path.join(
                  self.get_storage().location, key_name)
          return self._processed_key_name