public static int getRecordLength(ICachedMNode node) {
    if (node.isMeasurement()) {
      return getRecordLength(node.getAsMeasurementMNode());
    } else {
      return INTERNAL_NODE_LENGTH;
    }
  }
These offset rather than magic number may also be used to track usage of related field.
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/schemaengine/schemaregion/mtree/impl/pbtree/schemafile/RecordUtils.java