code: def create(self):
          
          # Calls each of these methods in order.  _populate_from_lines and
          # _update_relations must be implemented in subclasses.
          self._init_tables()
          self._populate_from_lines(self.iterator)
          self._update_relations()
          self._finalize()
docs: Calls various methods sequentially in order to fully build the
          database.