':return: True if I should grep this request/response pair. This method
replaces some of the logic that before was in grep_plugin.py,
but because of the requirement of a central location to store
a bloom filter was moved here.'

def should_grep(self, request, response):

    if (self.TARGET_DOMAINS is None):
        self.TARGET_DOMAINS = cf.cf.get('target_domains')
    if (not (response.get_url().get_domain() in self.TARGET_DOMAINS)):
        return False
    return self._already_analyzed.add(response.get_uri())
