Token he = sentence2.addToken(heStartIdx, heStartIdx + "He".length());
Set<Span> obamaMentions = new HashSet<Span>();
obamaMentions.add(he);
obama.addAnnotation(NlpAnnotations.COREF_ANNOTATION,
Value.value(new CorefFeature(true, obamaMentions)));
Set<Span> heMentions = new HashSet<Span>();
heMentions.add(obama);
he.addAnnotation(NlpAnnotations.COREF_ANNOTATION,
Value.value(new CorefFeature(false, heMentions)));
}