@Override
    public void fromData(PdxReader reader) {}
Have a PDX with an Object[] whose element is a DataSerializable which has a Long[]. Its a bug
if the array nested in the DS becomes an Object[] during deserialization. Demonstrates bug
43838.
geode-core/src/integrationTest/java/org/apache/geode/pdx/PdxInstanceFactoryJUnitTest.java