Destination of the coreference link for this word (if any).
It contains the index of the sentence and the index of the word that
are the end of this coref link. Both indices start at 1. The
sentence index is IntTuple.get(0); the token index in the
sentence is IntTuple.get(1).
Returns the type associated with this annotation. This method must
return the same class type as its value type parameter. It feels like
one should be able to get away without this method, but because Java
erases the generic type signature, that info disappears at runtime.