for (final IPortletWindow portletWindow : portletWindows) {
if(portletWindow != null) {
final IPortletWindowId portletWindowId = portletWindow.getPortletWindowId();
final WindowState windowState = portletWindow.getWindowState();
final PortletMode portletMode = portletWindow.getPortletMode();
cacheKeyBuilder.addAll(portletWindowId, windowState.toString(), portletMode.toString());
} else {
this.logger.warn("portletWindowRegistry#getAllLayoutPortletWindows() returned a null portletWindow");
}
}