* @throws AssertionError if the actual directionEstimator is not equal to the given one.
*
* @see ValueBoxBase#getDirectionEstimator()
*/
public S directionEstimatorEquals(DirectionEstimator expected) {
DirectionEstimator directionEstimator = actual.getDirectionEstimator();
if (areEqual(directionEstimator, expected))
return myself;
throw propertyComparisonFailed("DirectionEstimator", directionEstimator, expected);
}