class DittoAcknowledgementLabel implements AcknowledgementLabel {

    public static boolean contains(@Nullable final AcknowledgementLabel acknowledgementLabel) {
        if (null != acknowledgementLabel) {
            for (final AcknowledgementLabel dittoAcknowledgementLabel : values()) {
                if (dittoAcknowledgementLabel.equals(acknowledgementLabel)) {
                    return true;
                }
            }
        }
        return false;
    }

    private  DittoAcknowledgementLabel(final CharSequence labelValue);

}