 │   ├── class2       # folder containing documents of class 2
│   │   └── classN       # folder containing documents of class N
│   └── test
│       ├── class0       # folder containing documents of class 0
│       ├── class1       # folder containing documents of class 1
│       ├── class2       # folder containing documents of class 2
│       └── classN       # folder containing documents of class N

Each subfolder should contain documents in plai