@SuppressWarnings("unchecked")
public Map<ExternalId, Map<String, String>> getLastKnownValues(final List<ExternalId> securities) {
Map<ExternalId, Map<String, String>> result = Maps.newHashMap();
JedisPool jedisPool = _redisConnector.getJedisPool();
Jedis jedis = jedisPool.getResource();
Pipeline pipeline = jedis.pipelined();
//start transaction
pipeline.multi();
for (ExternalId identifier : securities) {
String redisKey = generateRedisKey(identifier.getScheme().getName(), identifier.getValue(), getNormalizationRuleSetId());
pipeline.hgetAll(redisKey);