code: def __register_driver(self, channel, webdriver):
          "Register webdriver to a channel."
  
          # Add to list of webdrivers to cleanup.
          if not self.__registered_drivers.has_key(channel):
              self.__registered_drivers[channel] = []  # set to new empty array
  
          self.__registered_drivers[channel].append(webdriver)
  
          # Set singleton instance for the channel
          self.__webdriver[channel] = webdrivef __register_driver(self, channel, webdriver):
          "Register webdriver to a channel."
  
          # Add to list of webdrivers to cleanup.
          if not self.__registered_drivers.has_key(channel):
              self.__registered_drivers[channel] = []  # set to new empty array
  
          self.__registered_drivers[channel].append(webdriver)
  
          # Set singleton instance for the channel
          self.__webdriver[channel] = webdriver
docs: Register webdriver to a channel.