How to use the getgauge.registry.ScreenshotsStore.pending_screenshots function in getgauge

def test_pending_screenshots(self):
        ScreenshotsStore.capture()
        pending_screenshots = ScreenshotsStore.pending_screenshots()
        self.assertEqual(1, len(pending_screenshots))
        self.assertTrue(os.path.exists(os.path.join(
            os.getenv("gauge_screenshots_dir"), pending_screenshots[0])))

os.getenv("gauge_screenshots_dir"), "screenshot{0}.png".format(uuid1()))

        def returns_abs_path():
            return first_screenshot

        def returns_base_ath():
            return os.path.basename(second_screenshot)
        registry.set_screenshot_provider(returns_abs_path, True)
        ScreenshotsStore.capture()
        self.assertEqual([os.path.basename(first_screenshot)],
                         ScreenshotsStore.pending_screenshots())

        registry.set_screenshot_provider(returns_base_ath, True)
        ScreenshotsStore.capture()
        self.assertEqual([os.path.basename(second_screenshot)],
                         ScreenshotsStore.pending_screenshots())

def test_pending_screenshots_gives_only_those_screenshots_which_are_not_collected(self):
        ScreenshotsStore.capture()
        pending_screenshots = ScreenshotsStore.pending_screenshots()
        self.assertEqual(1, len(pending_screenshots))
        screenshot_file = pending_screenshots[0]
        pending_screenshots = ScreenshotsStore.pending_screenshots()
        self.assertEqual(0, len(pending_screenshots))
        ScreenshotsStore.capture()
        pending_screenshots = ScreenshotsStore.pending_screenshots()
        self.assertEqual(1, len(pending_screenshots))
        self.assertNotEqual(screenshot_file, pending_screenshots[0])

def test_clear(self):
        ScreenshotsStore.capture()
        ScreenshotsStore.clear()
        pending_screenshots = ScreenshotsStore.pending_screenshots()
        self.assertEqual([], pending_screenshots)

def test_pending_screenshots_gives_only_those_screenshots_which_are_not_collected(self):
        ScreenshotsStore.capture()
        pending_screenshots = ScreenshotsStore.pending_screenshots()
        self.assertEqual(1, len(pending_screenshots))
        screenshot_file = pending_screenshots[0]
        pending_screenshots = ScreenshotsStore.pending_screenshots()
        self.assertEqual(0, len(pending_screenshots))
        ScreenshotsStore.capture()
        pending_screenshots = ScreenshotsStore.pending_screenshots()
        self.assertEqual(1, len(pending_screenshots))
        self.assertNotEqual(screenshot_file, pending_screenshots[0])

def _add_message_and_screenshots(response):
    response.executionResult.message.extend(MessagesStore.pending_messages())
    response.executionResult.screenshots.extend(
        ScreenshotsStore.pending_screenshots())

def _add_exception(e, response, continue_on_failure):
    if os.getenv('screenshot_on_failure') == 'true':
        screenshot = registry.screenshot_provider()()
        response.executionResult.screenShot = screenshot
        response.executionResult.failureScreenshot = screenshot
    response.executionResult.failed = True
    message = e.__str__()
    if not message:
        message = "Exception occurred"
    response.executionResult.errorMessage = message
    response.executionResult.stackTrace = traceback.format_exc()
    response.executionResult.errorType = ProtoExecutionResult.ASSERTION
    if continue_on_failure:
        response.executionResult.recoverableError = True
    response.executionResult.message.extend(MessagesStore.pending_messages())
    response.executionResult.screenshots.extend(ScreenshotsStore.pending_screenshots())