code: def _diff_vals(old, new, with_unchanged):
      if (
          isinstance(new, list)
          and isinstance(old, list)
          and len(old) == len(new) == 1
      ):
          return _diff_vals(old[0], new[0], with_unchanged)
  
      if not with_unchanged and old == new:
          return {}
  
      res = {"old": old, "new": new}
      if isinstance(new, (int, float)) and isinstance(
          old, (int, float)
      ):
          res["diff"] = new - old
  
      return res
  
file_path: dvc/dvc/utils/diff.py
imports: import json
  from collections import defaultdict
  from typing import Dict
  from .flatten import flatten
label_desc: Use image node_id 2 for calling a global function with example usage: _diff_vals(old, new, with_unchanged) and returns: res, _diff_vals, dict