### Question:
EntityReferenceConverter extends AbstractConverter<EntityReference> { @Override protected String convertToString(EntityReference value) { if (value == null) { return null; } return new Namespace(value.getType().getLowerCase(), this.serialier.serialize(value)).toString(); }    }### Answer:
@Test public void convertToString() { EntityReference reference; reference = new EntityReference("page", EntityType.DOCUMENT, new EntityReference("space", EntityType.SPACE, new EntityReference("wiki", EntityType.WIKI))); assertEquals("document:wiki:space.page", this.converterManager.convert(String.class, reference)); }