message: Update image.py
  Modified the Example of `ImageDataGenerator.flow` such that it resolves the Issue,
diff: @@ -669,12 +669,14 @@ class ImageDataGenerator(image.ImageDataGenerator):
  rotation_range=20,
  width_shift_range=0.2,
  height_shift_range=0.2,
  - horizontal_flip=True)
  + horizontal_flip=True,
  + validation_split = 0.2)
  # compute quantities required for featurewise normalization
  # (std, mean, and principal components if ZCA whitening is applied)
  datagen.fit(x_train)
  # fits the model on batches with real-time data augmentation:
  - model.fit(datagen.flow(x_train, y_train, batch_size=32),
  + model.fit(datagen.flow(x_train, y_train, batch_size=32, subset = 'training'),
  + validation_data = datagen.flow(x_train, y_train, batch_size=8, subset = 'validation'),
  steps_per_epoch=len(x_train) / 32, epochs=epochs)
  # here's a more "manual" example
  for e in range(epochs):
  