def get_action_instance(self, config=None):
        """
        Retrieve instance of the action class.
        """
        # pylint: disable=not-callable
        instance = get_action_class_instance(
            action_cls=self.action_cls,
            config=config,
            action_service=self.action_service,
        )
        return instance

        Retrieve instance of the action class.
        
st2tests/st2tests/actions.py