button = BUTTON2;
this.button = BUTTON2;
  public MouseEvent(Component source, int id, long when, int modifiers,                    int x, int y, int clickCount, boolean popupTrigger,                    int button)  {    super(source, id, when, modifiers);    this.x = x;    this.y = y;    this.clickCount = clickCount;    this.popupTrigger = popupTrigger;    this.button = button;    if (button < NOBUTTON || button > BUTTON3)      throw new IllegalArgumentException();    if ((modifiers & EventModifier.OLD_MASK) != 0)      {        if ((modifiers & BUTTON1_MASK) != 0)          button = BUTTON1;        else if ((modifiers & BUTTON2_MASK) != 0)          button = BUTTON2;        else if ((modifiers & BUTTON3_MASK) != 0)          button = BUTTON3;      }  }