Returns `True` when rule enabled.

        :rtype: bool

def is_enabled(self):
        """Returns `True` when rule enabled.

        :rtype: bool

        """
        if self.name in settings.exclude_rules:
            return False
        elif self.name in settings.rules:
            return True
        elif self.enabled_by_default and ALL_ENABLED in settings.rules:
            return True
        else:
            return False