code: def _process_key(self, key):
          
          # Handle the driver case first.
          if self.mode != ray.WORKER_MODE:
              if key.startswith(b"FunctionsToRun"):
                  with profiling.profile("fetch_and_run_function"):
                      self.fetch_and_execute_function_to_run(key)
              # Return because FunctionsToRun are the only things that
              # the driver should import.
              return
  
          if key.startswith(b"RemoteFunction"):
              with profiling.profile("register_remote_function"):
                  (self.worker.function_actor_manager.
                   fetch_and_register_remote_function(key))
          elif key.startswith(b"FunctionsToRun"):
              with profiling.profile("fetch_and_run_function"):
                  self.fetch_and_execute_function_to_run(key)
          elif key.startswith(b"ActorClass"):
              # Keep track of the fact that this actor class has been
              # exported so that we know it is safe to turn this worker
              # into an actor of that class.
              self.worker.function_actor_manager.imported_actor_classes.add(key)
          # TODO(rkn): We may need to bring back the case of
          # fetching actor classes here.
          else:
              raise Exception("This code should be unreachable.")
docs: Process the given export key from redis.