public final class SeriesRenderingOrder implements Serializable {

    /** For serialization. */
    private static final long serialVersionUID = 209336477448807735L;
    
    /**
     * Render series in the order 0, 1, 2, ..., N-1, where N is the number
     * of series.
     */
    public static final SeriesRenderingOrder FORWARD
            = new SeriesRenderingOrder("SeriesRenderingOrder.FORWARD");

    /**
     * Render series in the order N-1, N-2, ..., 2, 1, 0, where N is the
     * number of series.
     */
    public static final SeriesRenderingOrder REVERSE
            = new SeriesRenderingOrder("SeriesRenderingOrder.REVERSE");

    /** The name. */
    private String name;

    /**
     * Private constructor.
     *
     * @param name  the name.
     */
    private SeriesRenderingOrder(String name) {
        this.name = name;
    }

    /**
     * Returns a string representing the object.
     *
     * @return The string (never <code>null</code>).
     */
    public String toString() {
        return this.name;
    }

    /**
     * Returns <code>true</code> if this object is equal to the specified
     * object, and <code>false</code> otherwise.
     *
     * @param obj  the object (<code>null</code> permitted).
     *
     * @return A boolean.
     */
    public boolean equals(Object obj) {
        if (this == obj) {
            return true;
        }
        if (!(obj instanceof SeriesRenderingOrder)) {
            return false;
        }
        SeriesRenderingOrder order = (SeriesRenderingOrder) obj;
        if (!this.name.equals(order.toString())) {
            return false;
        }
        return true;
    }

    /**
     * Returns a hash code for this instance.
     * 
     * @return A hash code.
     */
    public int hashCode() {
        return this.name.hashCode();
    }
    
    /**
     * Ensures that serialization returns the unique instances.
     *
     * @return The object.
     *
     * @throws ObjectStreamException if there is a problem.
     */
    private Object readResolve() throws ObjectStreamException {
        if (this.equals(SeriesRenderingOrder.FORWARD)) {
            return SeriesRenderingOrder.FORWARD;
        }
        else if (this.equals(SeriesRenderingOrder.REVERSE)) {
            return SeriesRenderingOrder.REVERSE;
        }
        return null;