keras の InstanceNormalization でエラー

InstanceNormalization の実行でエラーがでます。

使用GitHubコード
GANs_in_Action Chapter9_CycleGAN

訂正前（インポートエラー）

Python
1from keras_contrib.layers.normalization import Instancenormalization
2
3ImportError: cannot import name 'Instancenormalization'

訂正後(小文字に変更)

Python
1from keras_contrib.layers.normalization import instancenormalization

訓練でのエラー内容

Python
1cycle_gan = CycleGAN()
2cycle_gan.train(epochs=100, batch_size=64, sample_interval=10)
3
4---------------------------------------------------------------------------
5NameError                                 Traceback (most recent call last)
6<ipython-input-69-c3c1044e578c> in <module>()
7----> 1 cycle_gan = CycleGAN()
8      2 cycle_gan.train(epochs=100, batch_size=64, sample_interval=10)
9
102 frames
11<ipython-input-64-6c3fc65fbb7c> in conv2d(layer_input, filters, f_size, normalization)
12      7         d = LeakyReLU(alpha=0.2)(d)
13      8         if normalization:
14----> 9             d = instanceNormalization()(d)
15     10         return d
16     11 
17
18NameError: name 'instanceNormalization' is not defined