Downloading more Images per class than required and that too randomly

I tried downloading the data with the  following command:

```
python ./downloader.py \
    -data_root /imagenet \
    -number_of_classes 19000 \
    -images_per_class 2 \
    -multiprocessing_workers 24
```

It downloaded arbitrary number of  images per class. I mean I am unable to see why this is happening. Some of the images in a class were 21 other were 3 and so on and so forth.