@Test
  public void testStructMapWithNull() throws IOException {
    Schema schema = new Schema(required(1, "id", Types.LongType.get()),
        required(2, "mapofstructs", Types.MapType.ofRequired(3, 4, Types.StringType.get(),
            Types.StructType.of(required(5, "something", Types.StringType.get()),
                required(6, "someone", Types.StringType.get()),
                required(7, "somewhere", Types.StringType.get())
            ))
        )
    );

    List<Record> records = TestHelper.RecordsBuilder.newInstance(schema)
        .add(0L, ImmutableMap.of())
        .build();

    testTables.createTable(shell, "mapwithnull", schema, fileFormat, records);

    List<Object[]> results = shell.executeStatement("select mapofstructs['context'].someone FROM mapwithnull");
    Assert.assertEquals(1, results.size());
    Assert.assertNull(results.get(0)[0]);
  }
Testing map-reduce inserts.
@throws IOException If there is an underlying IOException
iceberg/iceberg-handler/src/test/java/org/apache/iceberg/mr/hive/TestHiveIcebergInserts.java