@Override
  public String convertToDatabaseColumn(Map<String, String> attribute) {
    return GSON.toJson(attribute);
  }
@Test
  void convertToDatabaseColumn_oneElement() throws IOException {
    Map<String, String> map = new HashMap<>(8);
    map.put("a", "1");

    String expected = readAllContentOf("json/converter/element.1.json");
    assertEquals(expected, this.converter.convertToDatabaseColumn(map));
  }