### Question:
LESSObjectPropertyResourceReference implements LESSResourceReference { @Override public String serialize() { return String.format("LessXObjectProperty[%s]", entityReferenceSerializer.serialize(objectPropertyReference)); } LESSObjectPropertyResourceReference(ObjectPropertyReference objectPropertyReference, 
            EntityReferenceSerializer<String> entityReferenceSerializer,
            DocumentAccessBridge bridge); @Override boolean equals(Object o); @Override int hashCode(); @Override String getContent(String skin); @Override String serialize();  }### Answer:
@Test public void serialize() throws Exception { ObjectPropertyReference objectPropertyReference = new ObjectPropertyReference("property", new ObjectReference("class", new DocumentReference("wiki", "Space", "Document"))); LESSObjectPropertyResourceReference lessObjectPropertyResourceReference = new LESSObjectPropertyResourceReference(objectPropertyReference, entityReferenceSerializer, bridge); when(entityReferenceSerializer.serialize(eq(objectPropertyReference))).thenReturn("objPropertyRef"); assertEquals("LessXObjectProperty[objPropertyRef]", lessObjectPropertyResourceReference.serialize()); }