docs: public NotificationChain basicSetDefaultValue(XExpression newDefaultValue, NotificationChain msgs)
  	{
  		XExpression oldDefaultValue = defaultValue;
  		defaultValue = newDefaultValue;
  		if (eNotificationRequired())
  		{
  			ENotificationImpl notification = new ENotificationImpl(this, Notification.SET, SarlPackage.SARL_FORMAL_PARAMETER__DEFAULT_VALUE, oldDefaultValue, newDefaultValue);
  			if (msgs == null) msgs = notification; else msgs.add(notification);
  		}
  		return msgs;
  	}