### Question:
PathIdConverter implements AttributeConverter<PathId, String> { @Override public String toGraphProperty(PathId value) { if (value == null) { return null; } return value.getId(); }  @Override String toGraphProperty(PathId value); @Override PathId toEntityAttribute(String value); static final PathIdConverter INSTANCE; }### Answer:
@Test public void shouldConvertIdToString() { PathId pathId = new PathId("test_path_id"); String graphObject = PathIdConverter.INSTANCE.toGraphProperty(pathId); assertEquals(pathId.getId(), graphObject); }