Record convert(Object data) {
    return convert(data, null);
  }
@Test
  @SuppressWarnings("unchecked")
  public void testStructToString() throws Exception {
    Table table = mock(Table.class);
    when(table.schema()).thenReturn(SIMPLE_SCHEMA);
    RecordConverter converter = new RecordConverter(table, config);

    Struct nestedData = createNestedStructData();
    Record record = converter.convert(nestedData);

    String str = (String) record.getField("st");
    Map<String, Object> map = (Map<String, Object>) MAPPER.readValue(str, Map.class);
    assertThat(map).hasSize(MAPPED_CNT);
  }