@Test
  public void testWriteStructOfMapsInTable() throws IOException {
    Schema schema = new Schema(required(1, "id", Types.LongType.get()),
        required(2, "structofmaps", Types.StructType
            .of(required(3, "map1", Types.MapType.ofRequired(4, 5,
                Types.StringType.get(), Types.StringType.get())), required(6, "map2",
                Types.MapType.ofRequired(7, 8, Types.StringType.get(),
                    Types.StringType.get())))));
    List<Record> records = TestHelper.generateRandomRecords(schema, 5, 0L);
    testComplexTypeWrite(schema, records);
  }
Runs insert queries against Iceberg tables with complex type columns, such as arrays, structs and maps.
iceberg/iceberg-handler/src/test/java/org/apache/iceberg/mr/hive/TestHiveIcebergComplexTypeWrites.java