code: def __unregister_driver(self, channel):
          "Unregister webdriver"
          driver = self.__get_driver_for_channel(channel)
  
          if self.__registered_drivers.has_key(channel) \
                  and driver in self.__registered_drivers[channel]:
  
              self.__registered_drivers[channel].remove(driver)
  
          self.__webdriver[channel] = Nonf __unregister_driver(self, channel):
          "Unregister webdriver"
          driver = self.__get_driver_for_channel(channel)
  
          if self.__registered_drivers.has_key(channel) \
                  and driver in self.__registered_drivers[channel]:
  
              self.__registered_drivers[channel].remove(driver)
  
          self.__webdriver[channel] = None
docs: Unregister webdriver