public static final String CONSTRAINTS_Null_MESSAGE = "{constraints.Null.message}";

    /** The key of the message: {item} must be in the past. */
    public static final String CONSTRAINTS_Past_MESSAGE = "{constraints.Past.message}";

    /** The key of the message: {item} must match "{regexp}". */
    public static final String CONSTRAINTS_Pattern_MESSAGE = "{constraints.Pattern.message}";

    /** The key of the message: Past 24 Hours */
    public static final String LABELS_facet_timestamp_1day = "{labels.facet_timestamp_1day}";

    /** The key of the message: Past Week */
    public static final String LABELS_facet_timestamp_1week = "{labels.facet_timestamp_1week}";

    /** The key of the message: Past Month */