@Override
  public List<String> mapRow(Row element) {
    List<String> res = new ArrayList<>();

    Schema s = element.getSchema();
    for (int i = 0; i < s.getFieldCount(); i++) {
      res.add(convertFieldToString(s.getField(i).getType(), element.getValue(i)));
    }

    return res;
  }
@Test
  public void testEmptyRow() {
    Schema.Builder schemaBuilder = new Schema.Builder();
    Schema schema = schemaBuilder.build();

    Row.Builder rowBuilder = Row.withSchema(schema);
    Row row = rowBuilder.build();

    SingleStoreDefaultUserDataMapper mapper = new SingleStoreDefaultUserDataMapper();
    List<String> res = mapper.mapRow(row);

    assertEquals(0, res.size());
  }