docs: public NotificationChain basicSetLeft(Expression newLeft, NotificationChain msgs)
    {
      Expression oldLeft = left;
      left = newLeft;
      if (eNotificationRequired())
      {
        ENotificationImpl notification = new ENotificationImpl(this, Notification.SET, SimpleExpressionsPackage.OR_EXPRESSION__LEFT, oldLeft, newLeft);
        if (msgs == null) msgs = notification; else msgs.add(notification);
      }
      return msgs;
    }