code: @NotNull public Collection<Record> loadRecords(@NotNull Collection<String> keys, @NotNull CacheHeaders cacheHeaders) {
      List<Record> records = new ArrayList<>(keys.size());
      for (String key : keys) {
        final Record record = loadRecord(key, cacheHeaders);
        if (record != null) {
          records.add(record);
        }
      }
      return records;
    }
docs: Calls through to {@link NormalizedCache#loadRecord(String, CacheHeaders)}. Implementations should override this
  method if the underlying storage technology can offer an optimized manner to read multiple records.
  
  @param keys         The set of {@link Record} keys to read.
  @param cacheHeaders The cache headers associated with the request which generated this record.