Lun

Sorry the correct last line is `key2 should be [SS(), FT(f2), FT(f1)] rather than [FT(f2), FT(f1), SS()]`

``` >>> import mlens >>> mlens.__version__ '0.2.3' ```

Hi @flennerhag , Thanks for the reply. And... I found another bug here. :astonished: ## Code ```Python from mlens.utils import check_instances from sklearn.preprocessing import ( StandardScaler as SS, FunctionTransformer as...