def __init__(self, trigger_instance, trigger, rule, extra_info=False):
        """
        :param trigger_instance: TriggerInstance DB object.
        :type trigger_instance: :class:`TriggerInstanceDB``

        :param trigger: Trigger DB object.
        :type trigger: :class:`TriggerDB`

        :param rule: Rule DB object.
        :type rule: :class:`RuleDB`
        """
        self.trigger_instance = trigger_instance
        self.trigger = trigger
        self.rule = rule
        self.extra_info = extra_info

        # Base context used with a logger
        self._base_logger_context = {
            "rule": self.rule,
            "trigger": self.trigger,
            "trigger_instance": self.trigger_instance,
        }

        :param trigger_instance: TriggerInstance DB object.
        :type trigger_instance: :class:`TriggerInstanceDB``

        :param trigger: Trigger DB object.
        :type trigger: :class:`TriggerDB`

        :param rule: Rule DB object.
        :type rule: :class:`RuleDB`
        
st2reactor/st2reactor/rules/filter.py