code: def account_whitelist(
          self,
          account_to_whitelist,
          lists=["white"],  # set of 'white' and/or 'black'
          account=None,
          **kwargs
      ):
          
          if not account:
              if "default_account" in self.config:
                  account = self.config["default_account"]
          if not account:
              raise ValueError("You need to provide an account")
          account = Account(account, blockchain_instance=self)
          account_to_list = Account(account_to_whitelist, blockchain_instance=self)
  
          if not isinstance(lists, (set, list)):
              raise ValueError('"lists" must be of instance list()')
  
          new_listing = operations.Account_whitelist.no_listing
          if "white" in lists:
              new_listing += operations.Account_whitelist.white_listed
          if "black" in lists:
              new_listing += operations.Account_whitelist.black_listed
  
          op = operations.Account_whitelist(
              **{
                  "fee": {"amount": 0, "asset_id": "1.3.0"},
                  "authorizing_account": account["id"],
                  "account_to_list": account_to_list["id"],
                  "new_listing": new_listing,
              }
          )
          return self.finalizeOp(op, account, "active", **kwargs)
docs: Account whitelisting
  
              :param str account_to_whitelist: The account we want to add
                  to either the white- or the blacklist
              :param set lists: (defaults to ``('white')``). Lists the
                  user should be added to. Either empty set, 'black',
                  'white' or both.
              :param str account: (optional) the account to allow access
                  to (defaults to ``default_account``)