ted automatically
    val_pct=0.1,
    random_state=None,
    verbose=1,
):
    &#34;&#34;&#34;
    ```
    Returns corpus as sequence of word IDs.
    Assumes corpus is in the following folder structure:
    ├── datadir
    │   ├── train
    │   │   ├── class0       # folder containing documents of class 0
    │   │   ├── class1       # folder containing documents of class 1
    │   │   ├── class2       # folder containing documents of class 2
    │   │   └