@Override
  public ConnectorInsertTableHandle beginInsert(
      ConnectorSession session,
      ConnectorTableHandle tableHandle,
      List<ColumnHandle> columns,
      RetryMode retryMode) {
    IcebergTableHandle table = (IcebergTableHandle) tableHandle;
    Table icebergTable = loadTable(session, table.getSchemaTableName());

    validateNotModifyingOldSnapshot(table, icebergTable);
    validateNotPartitionedByNestedField(icebergTable.schema(), icebergTable.spec());

    beginTransaction(icebergTable);

    return newWritableTableHandle(table.getSchemaTableName(), icebergTable, retryMode);
  }
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