use dict instead of relying on list order

        for comment in self.comments:

            copied_comments.append(comment.copy())

        steps_by_id = {s.order_index: s for s in copied_workflow.steps}

        comments_by_id = {c.order_index: c for c in copied_workflow.comments}

        # copy comment relationships

        for old_comment, new_comment in zip(self.comments, copied_comments):

            for step_id in [step.order_index for step in old_comment.child_steps]:

                child_step = copied_workflow.steps[step_id]

                child_step = steps_by_id.get(step_id)

                if child_step:

                    child_step.parent_comment = new_comment

            for comment_id in [comment.order_index for comment in old_comment.child_comments]:

                child_comment = copied_workflow.comments[comment_id]

                child_comment = comments_by_id.get(comment_id)

                if child_comment:

                    child_comment.parent_comment = new_comment