docs: def return_single_features_base(dbpath, set_object, object_id):
      """
      Generic function which returns the features of an object specified by the object_id
  
      Parameters
      ----------
      dbpath : string, path to SQLite database file
      set_object : object (either TestSet or TrainSet) which is stored in the database
      object_id : int, id of object in database
  
      Returns
      -------
      features : dict containing the features
      """
      engine = create_engine('sqlite:////' + dbpath)
      session_cl = sessionmaker(bind=engine)
      session = session_cl()
      tmp_object = session.query(set_object).get(object_id)
      session.close()
      return tmp_object.features