code: def update(self, campaign_id, budget, nick=None):
          '''xxxxx.xxxxx.campaign.budget.update
          ===================================
          更新一个推广计划的日限额'''
          request = TOPRequest('xxxxx.xxxxx.campaign.budget.update')
          request['campaign_id'] = campaign_id
          request['budget'] = budget
          if nick!=None: request['nick'] = nick
          self.create(self.execute(request), fields=['success','result','success','result_code','result_message'], models={'result':CampaignBudget})
          return self.resulf update(self, campaign_id, budget, nick=None):
          '''xxxxx.xxxxx.campaign.budget.update
          ===================================
          更新一个推广计划的日限额'''
          request = TOPRequest('xxxxx.xxxxx.campaign.budget.update')
          request['campaign_id'] = campaign_id
          request['budget'] = budget
          if nick!=None: request['nick'] = nick
          self.create(self.execute(request), fields=['success','result','success','result_code','result_message'], models={'result':CampaignBudget})
          return self.result
docs: xxxxx.xxxxx.campaign.budget.update
          ===================================
          更新一个推广计划的日限额