code: def get_balance(self, acc_id=None, site='Pro', _async=False):
          
          acc_id = self.acc_id if acc_id is None else acc_id
          assert site in ['Pro', 'HADAX']
          path = f'/v1{"/" if site == "Pro" else "/hadax/"}account/accounts/{acc_id}/balance'
          # params = {'account-id': self.acct_id}
          params = {}
          return api_key_get(params, path, _async=_async)
docs: 获取当前账户资产
          :return: