Iterator i = externalTask.getSuccessorList().iterator();
Dependency dep;
realTask.invalidateSchedules();
while (i.hasNext()) {
dep = (Dependency)i.next();
dep.fireDeleteEvent(this);
dep.replace(realTask, true);
try {
dep.testValid(false);
} catch (InvalidAssociationException e) {
dep.setDisabled(true);