How to get output fields from .Json File using machineLearning Extractor

@alexcabuz This feature is so amazing!!! Already Started working today in this .
Done everything upto MachineLearningExtractor.
Will you guys help me on how can i get an individual values like all the fields from the dataset output (Say output Dataset : ds )
I am trying with for each activity and trying to print , but it was not expected filed results some random text i got …

Help me guys, what was the process to print all the field values from extracted json.