The random subset in Assemble does not contain more than one classes

[tsiakmaki]

Choosing randomly a subset of indexes at Assemble
https://github.com/YGZWQZD/LAMDA-SSL/blob/master/LAMDA_SSL/Algorithm/Classification/Assemble.py#L88
does not necessarily means that the subset will contain more than one classes. E.g. for small datasets.

Is there a workaround for this?

Thank you in advance.