private static Window getParentWindow(Component sourceComponent) {
		if (sourceComponent == null) {
			return getDefaultParentWindow();
		}
		Window window = WindowUtilities.windowForComponent(sourceComponent);
		if (window != null) {
			return window;
		}
		return getDefaultParentWindow();
	}
Area where user can mouse without hiding the window (in screen coordinates).  A.K.A., the
mouse neutral zone.
Ghidra/Framework/Docking/src/main/java/docking/widgets/PopupWindow.java