private void checkSerializable(Serializable before) throws IOException, ClassNotFoundException {
    ByteArrayOutputStream baos = new ByteArrayOutputStream();
    ObjectOutputStream oos = new ObjectOutputStream(baos);
    oos.writeObject(before);
    oos.close();
    byte[] bytes = baos.toByteArray();
    ByteArrayInputStream bais = new ByteArrayInputStream(bytes);
    ObjectInputStream ois = new ObjectInputStream(bais);
    Object after = ois.readObject();
    assertEquals(before, after);
  }
Have a pdx with an array of pdx. Make sure the array class does not get loaded during getField,
hashCode, and equals.
geode-core/src/integrationTest/java/org/apache/geode/pdx/PdxInstanceFactoryJUnitTest.java