docs: def get_max_id(cls, session):
          """Get the current max value of the ``id`` column.
  
          When creating and storing ORM objects in bulk, :mod:`sqlalchemy` does not automatically
          generate an incrementing primary key ``id``. To do this manually, one needs to know the
          current max ``id``. For ORM object classes that are derived from other ORM object classes,
          the max ``id`` of the lowest base class is returned. This is designed to be used with
          inheritance by joining, in which derived and base class objects have identical ``id`` values.
  
          Args:
              session: database session to operate in
          """
          # sqlalchemy allows only one level of inheritance, so just check this class and all its bases
          id_base = None
          for c in [cls] + list(cls.__bases__):
              for base_class in c.__bases__:
                  if base_class.__name__ == 'Base':
                      if id_base is None:
                          # we found our base class for determining the ID
                          id_base = c
                      else:
                          raise RuntimeError("Multiple base object classes for class " + cls.__name__)
  
          # this should never happen
          if id_base is None:
              raise RuntimeError("Error searching for base class of " + cls.__name__)
  
          # get its max ID
          max_id = session.query(func.max(id_base.id)).scalar()
  
          # if no object is present, None is returned
          if max_id is None:
              max_id = 0
  
          return max_id