### Question:
DefaultPieDataset extends AbstractDataset implements PieDataset, Cloneable, PublicCloneable, Serializable { public void setValue(Comparable key, Number value) { this.data.setValue(key, value); fireDatasetChanged(); } DefaultPieDataset();  DefaultPieDataset(KeyedValues data); @Override int getItemCount(); @Override List<Comparable> getKeys(); @Override Comparable getKey(int item); @Override int getIndex(Comparable key); @Override Number getValue(int item); @Override Number getValue(Comparable key); void setValue(Comparable key, Number value); void setValue(Comparable key, double value); void insertValue(int position, Comparable key, double value); void insertValue(int position, Comparable key, Number value); void remove(Comparable key); void clear(); void sortByKeys(SortOrder order); void sortByValues(SortOrder order); @Override boolean equals(Object obj); @Override int hashCode(); @Override Object clone();  }### Answer:
@Test public void testSerialization() throws IOException, ClassNotFoundException { DefaultPieDataset d1 = new DefaultPieDataset(); d1.setValue("C1", new Double(234.2)); d1.setValue("C2", null); d1.setValue("C3", new Double(345.9)); d1.setValue("C4", new Double(452.7)); DefaultPieDataset d2 = (DefaultPieDataset) TestUtilities.serialised(d1); assertEquals(d1, d2); }
@Test public void testSerialization() throws IOException, ClassNotFoundException { DefaultPieDataset d1 = new DefaultPieDataset(); d1.setValue("C1", new Double(234.2)); d1.setValue("C2", null); d1.setValue("C3", new Double(345.9)); d1.setValue("C4", new Double(452.7)); DefaultPieDataset d2 = (DefaultPieDataset) TestUtils.serialised(d1); assertEquals(d1, d2); }