code: def _sequence_query(self):
          
          klass = self.__class__
          query = klass.select().where(klass.sequence.is_null(False))
          seq_scope_field_names =\
              (self.__seq_scope_field_name__ or '').split(',')
          for name in seq_scope_field_names:
              seq_scope_field = getattr(klass, name, None)
              if seq_scope_field:
                  seq_scope_field_value = getattr(self, name)
                  query = query.where(seq_scope_field == seq_scope_field_value)
          return query
docs: query all sequence rows