`CompressedVignetteSet` with the following constructor
```
-def __init__(self, problem_number, nb_samples, batch_size, cuda = False, logger = None):
+__init__(problem_number, nb_samples, batch_size, cuda = False, logger = None)
```
and the following method to return one batch
```
-def get_batch(self, b):
+(torch.FloatTensor, torch.LongTensor) get_batch(b)
```
## Low-level functions ##