docs: def install_except_hook(except_hook=_hooks.except_hook):
      """
      Install an except hook that will show the crash report dialog when an
      unhandled exception has occured.
  
      :param except_hook: except_hook function that will be called on the main
          thread whenever an unhandled exception occured. The function takes
          two parameters: the exception object and the traceback string.
      """
      if not _backends:
          raise ValueError('no backends found, you must at least install one '
                           'backend before calling this function')
      global _except_hook
      _except_hook = _hooks.QtExceptHook(except_hook)