if (port instanceof IOPort) {
// Create a diagonal connector for multiports, if necessary.
IOPort ioPort = (IOPort) port;
if (ioPort.isMultiport()) {
int numberOfLinks = ioPort.linkedRelationList().size();
if (numberOfLinks > 1) {
// The diagonal is necessary.
CompositeFigure compositeFigure = new CompositeFigure(
figure) {