docs: def return_labels(self, original=False):
          """
          Returns the labels of the dataset
  
          Parameters
          ----------
          original : if True, will return original labels, if False, will return transformed labels (as defined by
          label_dict), default value: False
  
          Returns
          -------
          A list of lists, each 'inside list' corresponds to a single data point, each element of the 'inside list' is a
          label
          """
          if self._prepopulated is False:
              raise errors.EmptyDatabase(self.dbpath)
          else:
              engine = create_engine('sqlite:////' + self.dbpath)
              trainset.Base.metadata.create_all(engine)
              session_cl = sessionmaker(bind=engine)
              session = session_cl()
              return_list = []
              for i in session.query(trainset.TrainSet).order_by(trainset.TrainSet.id):
                  if original is True:
                      row_list = i.labels['original']
                  else:
                      row_list = i.labels['transformed']
                  return_list.append(row_list[:])
              session.close()
              return return_list