private List<ArrangeConstraint> getArrangeConstraints(final EObject diagramElement) {
List<ArrangeConstraint> constraints = null;
if (diagramElement instanceof AbstractDNode) {
final AbstractDNode node = (AbstractDNode) diagramElement;
constraints = node.getArrangeConstraints();
} else if (diagramElement instanceof DEdge) {
final DEdge edge = (DEdge) diagramElement;
constraints = edge.getArrangeConstraints();
}
return constraints;
}
