### Question:
OHLCSeriesCollection extends AbstractXYDataset implements OHLCDataset, Serializable { public void addSeries(OHLCSeries series) { if (series == null) { throw new IllegalArgumentException("Null 'series' argument."); } this.data.add(series); series.addChangeListener(this); fireDatasetChanged(); } OHLCSeriesCollection(); TimePeriodAnchor getXPosition(); void setXPosition(TimePeriodAnchor anchor); void addSeries(OHLCSeries series); @Override int getSeriesCount(); OHLCSeries getSeries(int series); @Override Comparable getSeriesKey(int series); @Override int getItemCount(int series); @Override double getXValue(int series, int item); @Override Number getX(int series, int item); @Override Number getY(int series, int item); @Override double getOpenValue(int series, int item); @Override Number getOpen(int series, int item); @Override double getCloseValue(int series, int item); @Override Number getClose(int series, int item); @Override double getHighValue(int series, int item); @Override Number getHigh(int series, int item); @Override double getLowValue(int series, int item); @Override Number getLow(int series, int item); @Override Number getVolume(int series, int item); @Override double getVolumeValue(int series, int item); void removeSeries(int index); boolean removeSeries(OHLCSeries series); void removeAllSeries(); @Override boolean equals(Object obj); @Override int hashCode(); @Override Object clone();  }### Answer:
@Test public void testSerialization() throws IOException, ClassNotFoundException { OHLCSeriesCollection c1 = new OHLCSeriesCollection(); OHLCSeries s1 = new OHLCSeries("Series"); s1.add(new Year(2006), 1.0, 1.1, 1.2, 1.3); c1.addSeries(s1); ByteArrayOutputStream buffer = new ByteArrayOutputStream(); ObjectOutput out = new ObjectOutputStream(buffer); out.writeObject(c1); out.close(); ObjectInput in = new ObjectInputStream( new ByteArrayInputStream(buffer.toByteArray())); OHLCSeriesCollection c2 = (OHLCSeriesCollection) in.readObject(); in.close(); assertEquals(c1, c2); }