/**
* Returns the type of this range's upper bound: {@link BoundType#CLOSED} if the range includes
* its upper endpoint, {@link BoundType#OPEN} if it does not.
*
* @throws IllegalStateException if this range is unbounded above (that is, {@link
* #hasUpperBound()} returns {@code false})
*/
public BoundType upperBoundType() {
return upperBound.typeAsUpperBound();
}
