def append(self, value):
        list_value = [value] if not isinstance(value, (list, tuple)) else value
        self.value = self._value + list_value
Tests the 'subscribe_ticker' and 'unsubscribe_ticker'
dataset/ETHPy150Open thasso/pyjip/jip/options.py/Option.append--crossover with--dataset/ETHPy150Open mhallsmoore/qstrader/price_handler/price_handler_test.py/TestPriceHandlerSimpleCase.test_subscribe_unsubscribe