code: public Coref newCoref(String id, List<Span<Term>> mentions) {
  	idManager.updateCounter(AnnotationType.COREF, id);
  	Coref newCoref = new Coref(id, mentions);
  	annotationContainer.add(newCoref, Layer.COREFERENCES, AnnotationType.COREF);
  	return newCoref;
      }
docs: Creates a coreference object to load an existing Coref. It receives it's ID as an argument. The Coref is added to the document.
  @param id the ID of the coreference.
  @param references different mentions (list of targets) to the same entity.
  @return a new coreference.