@Override
  public ConnectorMergeTableHandle beginMerge(
      ConnectorSession session, ConnectorTableHandle tableHandle, RetryMode retryMode) {
    IcebergTableHandle table = (IcebergTableHandle) tableHandle;
    verifyTableVersionForUpdate(table);

    Table icebergTable = loadTable(session, table.getSchemaTableName());
    validateNotModifyingOldSnapshot(table, icebergTable);
    validateNotPartitionedByNestedField(icebergTable.schema(), icebergTable.spec());

    beginTransaction(icebergTable);

    IcebergTableHandle newTableHandle = table.withRetryMode(retryMode);
    IcebergWritableTableHandle insertHandle =
        newWritableTableHandle(table.getSchemaTableName(), icebergTable, retryMode);

    return new IcebergMergeTableHandle(newTableHandle, insertHandle);
  }
Iceberg original metadata has some problems for mixed-format table, such as iceberg version,
table type. So copy from IcebergMetadata and made some change
amoro-format-mixed/amoro-mixed-trino/src/main/java/org/apache/amoro/trino/unkeyed/IcebergMetadata.java