docs: def trigger_action(self, action, key_value, modifier_mask):
          """Calls the appropriate callback function(s) for the given action
  
          :param str action: The name of the action that was triggered
          :param key_value: The key value of the shortcut that caused the trigger
          :param modifier_mask: The modifier mask of the shortcut that caused the trigger
          :return: Whether a callback was triggered
          :rtype: bool
          """
          res = False
          if action in self.__action_to_callbacks:
              for callback_function in self.__action_to_callbacks[action]:
                  try:
                      ret = callback_function(key_value, modifier_mask)
                      # If at least one controller returns True, the whole result becomes True
                      res |= (False if ret is None else ret)
                  except Exception as e:
                      logger.exception('Exception while calling callback methods for action "{0}": {1}'.format(action, e))
          return res