If Chromedriver is out-of-date, make it clear!
        Given the high popularity of the following StackOverflow article:
        https://stackoverflow.com/questions/49162667/unknown-error-
                call-function-result-missing-value-for-selenium-send-keys-even
        ... the original error message was not helpful. Tell people directly.
        (Only expected when using driver.send_keys() with an old Chromedriver.)

def __get_improved_exception_message(self):
        """
        If Chromedriver is out-of-date, make it clear!
        Given the high popularity of the following StackOverflow article:
        https://stackoverflow.com/questions/49162667/unknown-error-
                call-function-result-missing-value-for-selenium-send-keys-even
        ... the original error message was not helpful. Tell people directly.
        (Only expected when using driver.send_keys() with an old Chromedriver.)
        """
        exc_message = self.__get_exception_message()
        maybe_using_old_chromedriver = False
        if "unknown error: call function result missing" in exc_message:
            maybe_using_old_chromedriver = True
        if self.browser == 'chrome' and maybe_using_old_chromedriver:
            update = ("Your version of ChromeDriver may be out-of-date! "
                      "Please go to "
                      "https://sites.google.com/a/chromium.org/chromedriver/ "
                      "and download the latest version to your system PATH! "
                      "Or use: ``seleniumbase install chromedriver`` . "
                      "Original Exception Message: %s" % exc_message)
            exc_message = update
        return exc_message