@SuppressWarnings("nls")
    private void checkNotNull(Object sourceClass, Object eventSetName,
            Object alistenerType, Object listenerMethodName) {
        if (sourceClass == null) {
            throw new NullPointerException(Messages.getString("custom.beans.0C"));
        }
        if (eventSetName == null) {
            throw new NullPointerException(Messages.getString("custom.beans.53"));
        }
        if (alistenerType == null) {
            throw new NullPointerException(Messages.getString("custom.beans.54"));
        }
        if (listenerMethodName == null) {
            throw new NullPointerException(Messages.getString("custom.beans.52"));
        }
    }