def METHOD_NAME(self, plan: SceptrePlan):
    delete_msg = (
        "* The following obsolete stacks will be deleted (if they exist on AWS):\n"
    )
    stacks_list = ""
    for stack in plan:
        # It's possible there could be stacks in the plan that aren't obsolete because those
        # stacks depend on obsolete stacks. They won't pass validation, but that's not the
        # point of this method. We'll just skip those here and fail validation later.
        if not stack.obsolete:
            continue
        stacks_list += "{}{}{}\n".format(Fore.YELLOW, stack.name, Style.RESET_ALL)
    click.echo(delete_msg + stacks_list)