Having error/issues in running the prediction code

Hi, i am getting this error when i am trying to run your prediction notebook code:

*** Closing price prediction for AAPL ***
---------------------------------------------------------------------------
AttributeError Traceback (most recent call last)
in ()
2 print("*** Closing price prediction for {} *** ".format(stock_1))
3 pred = Predictor(stock_1)
----> 4 pred.select_model(verbose=1)
5 pred.graph()

~/Downloads/Stock-Prediction-using-LSTM-master/model.py in select_model(self, verbose)
61 self.__test_error = lowest_test_error
62 if verbose in [1,2]:
---> 63 print("==> Best model ticker {0:} with error of {1:.4f}".format(self.__best_model.ticker,self.__test_error))
64
65 def graph(self):

AttributeError: 'NoneType' object has no attribute 'ticker'

the above error occurs in the fourth block

Reproduce the failure in the notebook's fourth block using the reported AAPL input. Start at Predictor.select_model in model.py, especially the line formatting self.__best_model.ticker, and trace why the selected model is None. Done means the prediction notebook runs past select_model without this AttributeError and the resulting output is verified.

Written by the indexing model from the issue text.