@Nullable
  @Override
  public Rectangle onMouseMove(@NotNull MouseEvent event) {
    Rectangle buttonBounds = getCloseButtonScreenBounds();
    if (buttonBounds == null) {
      return null;
    }
    if (myCloseButton != null && !myCloseButton.isVisible()) {
      myCloseButton.setVisible(true);
      return buttonBounds;
    }
    boolean mouseOverButton = buttonBounds.contains(event.getLocationOnScreen());
    return (mouseOverButton ^ myCloseButtonHovered) ? buttonBounds : null;
  }
@Nullable
  @Override
  public Rectangle onMouseMove(@NotNull MouseEvent event)