The imports are a key piece:

#!/usr/bin/env python3
import sys
import numpy as np
from keras.layers import Dense, Reshape
from keras.layers import BatchNormalization
from keras.layers.advanced_activations import LeakyReLU
from keras.models import Sequential, Model
from keras.optimizers import Adam

As in previous classes, you will need the availability of sys and numpy. The basic layer types are imported for use in the model, along with the LeakyReLU activation layer. The Adam optimizer is used here, but a exercise problem is to expand each class to have a different optimizer available.