code: def check_ip(self, ip):
          
  
          self._last_result = None
  
          if is_valid_ipv4(ip):
              key = None
              if self._use_cache:
                  key = self._make_cache_key(ip)
                  self._last_result = self._cache.get(key, version=self._cache_version)
  
              if self._last_result is None:
                  # request httpBL API
                  error, age, threat, type = self._request_httpbl(ip)
                  if error == 127 or error == 0:
                      self._last_result = {
                          'error': error,
                          'age': age,
                          'threat': threat,
                          'type': type
                      }
                      if self._use_cache:
                          self._cache.set(key, self._last_result, timeout=self._api_timeout, version=self._cache_version)
              if self._last_result is not None and settings.CACHED_HTTPBL_USE_LOGGING:
                  logger.info(
                      'httpBL check ip: {0}; '
                      'httpBL result: error: {1}, age: {2}, threat: {3}, type: {4}'.format(ip,
                                                                                           self._last_result['error'],
                                                                                           self._last_result['age'],
                                                                                           self._last_result['threat'],
                                                                                           self._last_result['type']
                                                                                           )
                  )
  
          return self._last_result
docs: Check IP trough the httpBL API
  
          :param ip: ipv4 ip address
          :return: httpBL results or None if any error is occurred