code: def prepare(self, data_source):
          
          dataframe = self.__get_dataframe(data_source, use_target=True)
          self.__config.get_data_model().set_features_types_from_dataframe(dataframe)
          dataframe = self.__cleaner.prepare(dataframe)
          return self.__transformer.prepare(dataframe)
docs: Called with the training data.
          @param data_source: Either a pandas.DataFrame or a file-like object.