code: def vocab_account_type(instance):
      
      for key, obj in instance['objects'].items():
          if 'type' in obj and obj['type'] == 'user-account':
              try:
                  acct_type = obj['account_type']
              except KeyError:
                  continue
              if acct_type not in enums.ACCOUNT_TYPE_OV:
                  yield JSONError("Object '%s' is a User Account Object "
                                  "with an 'account_type' of '%s', which is not a "
                                  "value in the account-type-ov vocabulary."
                                  % (key, acct_type), instance['id'], 'account-type')
docs: Ensure a user-account objects' 'account-type' property is from the
      account-type-ov vocabulary.