code: def testExamples(frontend, f):
      name, file = f
      global path
      fn = os.path.join(path, file)
      os.chdir(path)
      sys.stdout.write(f"{name}")
      sys.stdout.flush()
      import1 = "import %s" % frontend if frontend != "" else ""
      import2 = os.path.splitext(os.path.split(fn)[1])[0]
      code = """
  try:
      {0}
      import faulthandler
      faulthandler.enable()
      import pyqtgraph as pg
      import {1}
      import sys
      print("test complete")
      sys.stdout.flush()
      pg.Qt.QtCore.QTimer.singleShot(1000, pg.Qt.QtWidgets.QApplication.quit)
      pg.exec()
      names = [x for x in dir({1}) if not x.startswith('_')]
      for name in names:
          delattr({1}, name)
  except:
      print("test failed")
      raise
  
  """.format(
          import1, import2
      )
      env = dict(os.environ)
      example_dir = os.path.abspath(os.path.dirname(__file__))
      path = os.path.dirname(os.path.dirname(example_dir))
      env["PYTHONPATH"] = f"{path}{os.pathsep}{example_dir}"
      process = subprocess.Popen(
          [sys.executable],
          stdin=subprocess.PIPE,
          stderr=subprocess.PIPE,
          stdout=subprocess.PIPE,
          text=True,
          env=env,
      )
      process.stdin.write(code)
      process.stdin.close()
  
      output = ""
      fail = False
      while True:
          try:
              c = process.stdout.read(1)
          except IOError as err:
              if err.errno == errno.EINTR:
                  # Interrupted system call; just try again.
                  c = ""
              else:
                  raise
          output += c
          if output.endswith("test complete"):
              break
          if output.endswith("test failed"):
              fail = True
              break
      start = time.time()
      killed = False
      while process.poll() is None:
          time.sleep(0.1)
          if time.time() - start > 2.0 and not killed:
              process.kill()
              killed = True
  
      stdout, stderr = (process.stdout.read(), process.stderr.read())
      process.stdout.close()
      process.stderr.close()
  
      if fail or "Exception:" in stderr or "Error:" in stderr:
          if (
              not fail
              and name == "RemoteGraphicsView"
              and "pyqtgraph.multiprocess.remoteproxy.ClosedError"
              in stderr
          ):
              # This test can intermittently fail when the subprocess is killed
              return None
          print(stdout)
          print(stderr)
          pytest.fail(
              f"{stdout}\n{stderr}\nFailed {name} Example Test Located in {file}",
              pytrace=False,
          )
  
file_path: pyqtgraph/pyqtgraph/examples/test_examples.py
imports: import contextlib
  import errno
  import importlib
  import itertools
  import os
  import platform
  import subprocess
  import sys
  import time
  from argparse import Namespace
  from collections import namedtuple
  import pytest
  from pyqtgraph import Qt
  from .None import utils
label_desc: Use image node_id 2 for calling a global function with example usage: testExamples(frontend, f) and returns: None