code: def test_single_request(self, connect):
      with gr.Blocks() as demo:
          name = gr.Textbox()
          output = gr.Textbox()
  
          def greet(x):
              return f"Hello, {x}!"
  
          name.submit(greet, name, output)
  
      with connect(demo) as client:
          job = client.submit("x", fn_index=0)
          assert job.result() == "Hello, x!"
  
file_path: gradio/test/test_queueing.py
imports: import time
  from concurrent.futures import wait
  import gradio_client
  import pytest
  from fastapi.testclient import TestClient
  import gradio
label_desc: Use image node_id 1 for calling the TestQueueing obj's underlying member method code with example usage: obj.test_single_request(connect) and returns: str, x, str