public static long computeHash(StructLike struct) {
    long partHash = -1;
    if (struct != null) {
      Object[] partFields = new Object[struct.size()];
      for (int i = 0; i < struct.size(); ++i) {
        partFields[i] = struct.get(i, Object.class);
      }
      partHash = Objects.hash(partFields);
    }
    return partHash;
  }
Get the new record from the updated record. Populate the `newRecord` with the filed values from `rec`.
@param rec The record read by the file scan task, which contains both the metadata fields and the row data fields
@param newRecord The record object to populate. The end result is the new record after the update.
iceberg/iceberg-handler/src/main/java/org/apache/iceberg/mr/hive/IcebergAcidUtil.java