code: function(serviceName)
      {
          var app = this;
          var services = {};
          try
          {
              if(app.services.hasOwnProperty(serviceName)){
                  services = app.services[serviceName];
              }else{                
                  throw "not found";
              }
          }
          catch(e)
          {
              var objFilePath = path.join(app._path,"services",serviceName);
              if(fs.existsSync(objFilePath+".js"))
              {
                  var serviceConfig = require(objFilePath);
                  if(typeof app.services != "object") app.services={};
                  app.services[serviceName]= serviceConfig;                    
                  services = serviceConfig;
              }
          }
          return services;
      }
docs: Get specified openbiz pre-defined system nls.
  
  This method it part of {@link openbiz.objects.Application},
  please never call this directly by ObjectService.
  
  if need to call this method, you have to use javascript's function.apply(applicationPointer,params)
  please see sample
  @memberof openbiz.services.ObjectService
  @param {string} serviceName, eg: EmailService
  @returns object
  
  @example
  // object will looks like below
  // {
  //    sendInviteMail: function(email, token, language){ }
  // }
  var EmailService = app.openbiz.apps.core.services['getService'];
  
  EmailService.sendInviteMail('xiuxu123@live.cn', 'xxxx-xx-xxx', 'zh-CN');