code: def test_grpc_stream_transient_error_iterable_input(
      port_generator, mocker
  ):
      random_port = port_generator()
      stop_event = multiprocessing.Event()
      start_event = multiprocessing.Event()
      t = multiprocessing.Process(
          target=_start_runtime,
          args=("grpc", random_port, "flow", stop_event, start_event),
      )
      t.start()
      start_event.wait(5)
      max_attempts = 5
      initial_backoff = 0.8
      backoff_multiplier = 1.5
      max_backoff = 5
      try:
          client = Client(host=f"grpc://localhost:{random_port}")
  
          for attempt in range(1, max_attempts + 1):
              try:
                  on_error_mock = mocker.Mock()
                  response = client.post(
                      "/",
                      random_docs(1),
                      request_size=1,
                      on_error=on_error_mock,
                      return_responses=True,
                      timeout=0.5,
                  )
                  assert len(response) == 1
  
                  on_error_mock.assert_not_called()
              except ConnectionError as err:
                  sync_wait_or_raise_err(
                      attempt=attempt,
                      err=err,
                      max_attempts=max_attempts,
                      backoff_multiplier=backoff_multiplier,
                      initial_backoff=initial_backoff,
                      max_backoff=max_backoff,
                  )
      finally:
          stop_event.set()
          t.join(5)
          t.terminate()
  
file_path: jina/tests/unit/clients/python/test_client_errors.py
imports: import multiprocessing
  import os
  import pytest
  from jina import Deployment, DocumentArray, Flow
  from jina.clients import Client
  from jina.clients.base.retry import wait_or_raise_err, sync_wait_or_raise_err
  from tests import random_docs
label_desc: Use image node_id 3 for calling a global function with example usage: test_grpc_stream_transient_error_iterable_input(port_generator, mocker) without return types