Create an iteration for the experiment group (works for grid and random).

def create_iteration(self, num_suggestions):
        """Create an iteration for the experiment group (works for grid and random)."""
        from db.models.experiment_groups import ExperimentGroupIteration

        iteration_config = BaseIterationConfig(iteration=0,
                                               num_suggestions=num_suggestions,
                                               experiment_ids=[])

        return ExperimentGroupIteration.objects.create(
            experiment_group=self.experiment_group,
            data=iteration_config.to_dict())