Storing results in database crashes when using a feature union
When the dbispipeline stores the results, the pipeline configuration is extracted from the pipeline object. The code differentiates three cases, where the last case is for when a "transformer_list" is available, which is the case, e.g., when a feature union is used. The code then tries to extract the individual transformers and expects the "transformer_list" to be of type dictionary, as a method "items()" is called, but as the name suggests, that variable is of type list when using "sklearn.pipeline.FeatureUnion".