*/
public void setIsEssential(boolean newIsEssential) {
boolean oldIsEssential = isEssential;
isEssential = newIsEssential;
if (eNotificationRequired())
eNotify(new ENotificationImpl(this, Notification.SET, OntoUMLPackage.MERONYMIC__IS_ESSENTIAL, oldIsEssential, isEssential));
}