public static long memoryOfIDeviceID2StrList(Map<IDeviceID, List<String>> map) {
    long usageInBytes = 0L;
    for (Map.Entry<IDeviceID, List<String>> entry : map.entrySet()) {
      usageInBytes += entry.getKey().ramBytesUsed();
      for (String str : entry.getValue()) {
        usageInBytes += MemUtils.getStringMem(str);
      }
    }
    return usageInBytes + 16L; // add the overhead of map
  }
Estimates memory usage of a {@link Map}<{@link IDeviceID}, {@link List}<{@link String}>>.
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/pipe/resource/memory/PipeMemoryWeightUtil.java