Should it be nn.ModuleList? 

Should it be nn.ModuleList? 
Also, you actually consider ModuleDict as well. Just a suggestion, maybe it is worth mentioning in the beginning not three main building blocks but rather four, just for the sake of consistency. And then add the fourth line below as well.
```
import torch.nn as nn

# nn.Module
# nn.Sequential
# nn.Module # here
# nn.ModuleDict # here
```