Google colab + Tensorflow: how to fix No module 'layers' error?

Question

Python

How to fix the error?

import tensorflow as tf
from layers import (_causal_linear, _output_linear, conv1d, dilated_conv1d)

Writes no module layers.
As far as I understand, layers is something like tf.layers Run
Google colab in an empty project, python3 GPU
Code source: https://raw.githubusercontent.com/tomlepaine/fast-...
(3rd and 4th lines)

Answer 1

https://programtalk.com/vs2/python/13192/fast-wave...
In the original (?) example, next to models.py is layers.py, in which all these layers are defined.