Add --username and --password options
          :param bool use_store: Name of the section (concept, command line options, API reference)

def add_username_password(self, use_store=False):
        """ Add --username and --password options
          :param bool use_store: Name of the section (concept, command line options, API reference)
        """
        self.argparser.add_argument('--username', default=None, help='Username')
        self.argparser.add_argument('--password', default=None, help='Password')
        self.argparser.add_argument('--clear-store', action='store_true', default=False, help='Clear password keystore')

        self.use_username_password_store = use_store