code: def normalize_dict(dictionary, **kwargs):
      
      result = {}
      if isinstance(dictionary, dict):
          keys = list(dictionary.keys())
          for key in keys:
              result[normalizer(key, **kwargs)] = normalize_dict(dictionary.get(key), **kwargs)
      else:
          result = dictionary
      return result
docs: Given an dict, normalize all of their keys using normalize function.