code: public static <T> Set<T> toSet(Iterator<? extends T> iterator) {
  		return Sets.newLinkedHashSet(toIterable(iterator));
  	}
docs: Returns a set that contains all the unique entries of the given iterator in the order of their appearance.
  The result set is a copy of the iterator with stable order.
  
  @param iterator
  the iterator. May not be <code>null</code>.
  @return a set with the unique entries of the given iterator. Never <code>null</code>.