ظهور الخطأ التالي 'AttributeError: 'Model' object has no attribute 'predict_classes أثناء استخدام الصف Model في keras  و TensorFlow

قمت ببناء نموذج تصنيف صور واستخدمت الصف Model في بناء النموذج  ظهور الخطأ التالي AttributeError: 'Model' object has no attribute 'predict_classes:

m = Sequential()
m.add(Flatten(input_shape=base_model.output_shape[1:]))
m.add(Dense(256, activation='tanh'))
m.add(Dense(3, activation='softmax'))
m.load_weights(top_model_weights_path)
model = Model(inputs=base_model.input, outputs=top_model(base_model.output))
for layer in model.layers[:15]: 
        layer.trainable = False
model.summary()
model.compile(loss='binary_crossentropy', optimizer=SGD(lr=1e-4, momentum=0.99), metrics=['accuracy'])
model.fit_generator(train_generator,
    steps_per_epoch=nb_train_samples // batch_size,
    epochs=epochs,
    validation_data=validation_generator,
    validation_steps=nb_validation_samples // batch_size,
    verbose=1)
model.save_weights(top_model_weights_path)
bottleneck_features_validation = model.predict_generator(validation_generator, nb_validation_samples // batch_size)
np.save(open('bottleneck_features_validation','wb'), bottleneck_features_validation)
validation_data = np.load(open('bottleneck_features_validation', 'rb'))
pred = model.predict_classes(validation_data)