private List<K> lookupCache(List<K> keys, Map<K, V> records, Object ... args) {
    List<K> missKeys = new ArrayList<>();
    records.putAll(cache.getAll(keys, args));
    keys.forEach(k -> {
      if (!records.containsKey(k)) {
        missKeys.add(k);
      }
    });
    return missKeys;
  }
Lookup the cache and return the keys that are missed in cache
@param keys keys to be looked up
@param records result map
@return list of keys missed in the cache
samza-core/src/main/java/org/apache/samza/table/caching/CachingTable.java