sort using Sort

In the method I need to implement sorting of the List using an object of the Sort class, but I did it using the usual sort method, but this does not work, explain and show me how to sort correctly using the object of the Sort class

public Iterable<PObject> findAll(Sort sort) { if (Boolean.TRUE) { throw new NotImplementedException("Not implemented yet"); } ObjectMapper objectMapper = new ObjectMapper(); List pObjectList = null; try { pObjectList = objectMapper.readValue(file, List.class); if (sort != null) { Collections.sort(pObjectList); } } catch (IOException e) { e.printStackTrace(); } return pObjectList;