code: def test_processing_error(self):
      io = Interface(lambda x: 1 / x, "number", "number")
      app, _, _ = io.launch(show_error=True, prevent_thread_lock=True)
      client = TestClient(app)
      response = client.post(
          "/api/predict/", json={"data": [0], "fn_index": 0}
      )
      assert response.status_code == 500
      assert "error" in response.json()
      io.close()
  
file_path: gradio/test/test_networking.py
imports: import os
  import urllib
  import warnings
  import pytest
  from fastapi.testclient import TestClient
  import gradio
  from gradio import Interface, networking
label_desc: Use image node_id 1 for calling the TestInterfaceErrors obj's underlying member method code with example usage: obj.test_processing_error() without return types