code: def iter_dict_differences(a, b):
      
      common_keys = set(a).union(b)
      for k in common_keys:
          a_value = a.get(k)
          b_value = b.get(k)
          if a_value != b_value:
              yield k, (a_value, b_value)
docs: Returns a generator yielding all the keys that have values that differ between each dictionary.