code: def watch_active_servings(dk_api, kitchen, period):
          
          print 'period', period
  
          # try:
          #     p = int(period)
          # except ValueError:
          #     return 'DKCloudCommand.watch_active_servings requires an integer for the period'
          if period <= 0:
              return 'DKCloudCommand.watch_active_servings requires a positive period'
  
          DKActiveServingWatcherSingleton().set_sleep_time(period)
          DKActiveServingWatcherSingleton().set_api(dk_api)
          DKActiveServingWatcherSingleton().set_kitchen(kitchen)
          DKActiveServingWatcherSingleton().start_watcher()
          return ""
docs: returns a string.
          :param dk_api: -- api object
          :param kitchen: string
          :param period: integer
          :rtype: string