def METHOD_NAME():
  """Create test ROOT_DIR for the trusted host."""
  root_path = os.path.join(_test_data_dir(), 'test_root')
  if os.path.exists(root_path):
    shutil.rmtree(root_path, ignore_errors=True)
  real_root = os.environ['ROOT_DIR']
  os.makedirs(root_path)
  # TODO(ochang): Make sure we don't copy files that aren't tracked in git.
  shutil.copytree(
      os.path.join(real_root, 'bot'), os.path.join(root_path, 'bot'))
  shutil.copytree(
      os.path.join(real_root, 'resources'), os.path.join(
          root_path, 'resources'))
  os.mkdir(os.path.join(root_path, 'src'))
  shutil.copytree(
      os.path.join(real_root, 'src', 'appengine'),
      os.path.join(root_path, 'src', 'appengine'))
  shutil.copytree(
      os.path.join(real_root, 'src', 'python'),
      os.path.join(root_path, 'src', 'python'))
  shutil.copytree(
      os.path.join(real_root, 'src', 'clusterfuzz'),
      os.path.join(root_path, 'src', 'clusterfuzz'))
  shutil.copytree(
      os.path.join(real_root, 'src', 'third_party'),
      os.path.join(root_path, 'src', 'third_party'))
  return root_path