Test URLs for being listed by the service.

        :param urls: a sequence of URLs  to be tested
        :returns: a tuple containing chunk of URLs and a response
        pertaining to them if the code of response was 200, which
        means at least one of the queried URLs is matched in either
        the phishing, malware, or unwanted software lists.

def _query(self, urls):
        """Test URLs for being listed by the service.

        :param urls: a sequence of URLs  to be tested
        :returns: a tuple containing chunk of URLs and a response
        pertaining to them if the code of response was 200, which
        means at least one of the queried URLs is matched in either
        the phishing, malware, or unwanted software lists.
        """
        urls = list(set(urls))
        for i in range(0, len(urls), self.max_urls_per_request):
            chunk = urls[i:i+self.max_urls_per_request]
            response = self._query_once(chunk)
            if response.status_code == 200:
                yield chunk, response