Take an event and run it through configured filters.

        Returns True if event should be stored, else False

def _filter(self, event):
        '''
        Take an event and run it through configured filters.

        Returns True if event should be stored, else False
        '''
        tag = event['tag']
        if self.opts['event_return_whitelist']:
            ret = False
        else:
            ret = True
        for whitelist_match in self.opts['event_return_whitelist']:
            if fnmatch.fnmatch(tag, whitelist_match):
                ret = True
                break
        for blacklist_match in self.opts['event_return_blacklist']:
            if fnmatch.fnmatch(tag, blacklist_match):
                ret = False
                break
        return ret