code: def get_function_descriptor_list(self):
          
          descriptor_list = []
          if self.is_for_driver_task:
              # Driver task returns an empty list.
              return descriptor_list
          else:
              descriptor_list.append(self.module_name.encode("ascii"))
              descriptor_list.append(self.class_name.encode("ascii"))
              descriptor_list.append(self.function_name.encode("ascii"))
              if len(self._function_source_hash) != 0:
                  descriptor_list.append(self._function_source_hash)
              return descriptor_list
docs: Return a list of bytes representing the function descriptor.
  
          This function is used to pass this function descriptor to backend.
  
          Returns:
              A list of bytes.