Iterator<ActivityInterface> itr = subActivities.iterator();
while (itr.hasNext()) {
activity = itr.next();
activityExitCoords = activity.getExitArrowCoords();
activityEntryCoords = activity.getEntryArrowCoords();
subGroup.appendChild(getArrowDefinition(doc, myStartCoords.getXLeft(),
myStartCoords.getYTop(), activityEntryCoords.getXLeft(),
activityEntryCoords.getYTop(), id, activity, activity));
subGroup.appendChild(getArrowDefinition(doc, activityExitCoords.getXLeft(),
activityExitCoords.getYTop(), myExitCoords.getXLeft(),
myExitCoords.getYTop(), id, activity, activity));