Overrides the current file detector (if necessary) in limited context.
        Ensures the original file detector is set afterwards.

        Example:

        with webdriver.file_detector_context(UselessFileDetector):
            someinput.send_keys('/etc/hosts')

        :Args:
         - file_detector_class - Class of the desired file detector. If the class is different
             from the current file_detector, then the class is instantiated with args and kwargs
             and used as a file detector during the duration of the context manager.
         - args - Optional arguments that get passed to the file detector class during
             instantiation.
         - kwargs - Keyword arguments, passed the same way as args.

def file_detector_context(self, file_detector_class, *args, **kwargs):
        """
        Overrides the current file detector (if necessary) in limited context.
        Ensures the original file detector is set afterwards.

        Example:

        with webdriver.file_detector_context(UselessFileDetector):
            someinput.send_keys('/etc/hosts')

        :Args:
         - file_detector_class - Class of the desired file detector. If the class is different
             from the current file_detector, then the class is instantiated with args and kwargs
             and used as a file detector during the duration of the context manager.
         - args - Optional arguments that get passed to the file detector class during
             instantiation.
         - kwargs - Keyword arguments, passed the same way as args.
        """
        last_detector = None
        if not isinstance(self.file_detector, file_detector_class):
            last_detector = self.file_detector
            self.file_detector = file_detector_class(*args, **kwargs)
        try:
            yield
        finally:
            if last_detector is not None:
                self.file_detector = last_detector