code: def count_account(self, domain):
          
          selector = domain.to_selector()
          cos_list = self.request_list('CountAccount', {'domain': selector})
          ret = []
  
          for i in cos_list:
              count = int(i['_content'])
              ret.append((zobjects.ClassOfService.from_dict(i),  count))
  
          return list(ret)
docs: Count the number of accounts for a given domain, sorted by cos
  
          :returns: a list of pairs <ClassOfService object>,count