class_docstr: A `Reference` specifies a possible output and how good/bad it is.  This
  could be used to represent multiple reference outputs which are all
  acceptable (e.g., in machine translation) or alternatives (e.g., in a
  multiple-choice exam).
code: def render_lines(self) -> List[str]:
      return [
          f"reference {format_tags(self.tags)}: {format_text(self.output.text)}"
      ]
  
imports: from abc import ABC, abstractmethod
  from dataclasses import dataclass, field, replace
  from typing import List, Optional, Tuple
  import re
  import inspect
  from helm.common.object_spec import ObjectSpec, create_object
  from helm.common.general import format_text, format_split, format_tags, indent_lines
  from helm.benchmark.augmentations.perturbation_description import PerturbationDescription
label_desc: Use image node_id 2 for calling the Reference obj's underlying member method code with example usage: obj.render_lines() and returns: list