protected void update(Callback callback) {
		isUpdating = true;
		try {
			callback.call();
		}
		finally {
			isUpdating = false;
		}
	}
Returns true if the theme system is in the process of updating
@return true if the theme system is in the process of updating
Ghidra/Framework/Gui/src/main/java/generic/theme/ThemeManager.java