public List<String> getThemeStyleSheets() {
final List<String> result;
if (contentGroup.getStylesheets().isEmpty()) {
result = null;
} else {
result = contentGroup.getStylesheets();
}
return result;
}
public void setPreviewStyleSheets(List<String> previewStyleSheets) {
contentGroup.getStylesheets().clear();
contentGroup.getStylesheets().addAll(previewStyleSheets);
contentGroup.applyCss();
}