final RelativeCompass direction, final FObj fobj) {
final ValueCollection collection = (ValueCollection) value();
final int whichElement = PropertyCollection.whichElementForDirectional(
direction, collection.getCount());
final PropertyValue value = collection.getItem(whichElement);
if (value.canEvalLength()) {
return this.convertValueToLength(value, fobj, context);
}
if (value.canEvalKeyword()) {
final FoPropertyKeyword keyword = (FoPropertyKeyword) value;
final FoValue keywordValue = keyword.getValue();