code: def get_account_cos(self, account):
          
          resp = self.request(
              'GetAccountInfo', {'account': account.to_selector()})
          return zobjects.COS.from_dict(resp['cos'])
docs: Fetch the cos for a given account
  
          Quite different from the original request which returns COS + various
          URL + COS + zimbraMailHost... But all other informations are accessible
          through get_account.
  
          :type account: zobjects.Account
          :rtype: zobjects.COS