Error when putting PO model to CCache

[Ru...@amxware.com]

I am experiencing an error when putting PO object into CCache.

This happened because Null class not implements Serializable. The error disappear when I add that implementation.

But since org.compiere.model.Null exist in base plugins, is there any workaround that I can implement? without building base plugin? 

or if that is the only way, do I need to create zip from source code?

caused by: java.io.NotSerializableException: org.compiere.model.Null
 at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1184)
 at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1378)
 at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1174)
 at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
 at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
 at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
 at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
 at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
 at com.hazelcast.nio.serialization.DefaultSerializers$ObjectSerializer.write(DefaultSerializers.java:223)
 at com.hazelcast.nio.serialization.StreamSerializerAdapter.write(StreamSerializerAdapter.java:37)
 at com.hazelcast.nio.serialization.SerializationServiceImpl.toData(SerializationServiceImpl.java:227)
 at com.hazelcast.nio.serialization.SerializationServiceImpl.toData(SerializationServiceImpl.java:207)
 at com.hazelcast.map.impl.MapServiceContextImpl.toData(MapServiceContextImpl.java:337)
 at com.hazelcast.map.impl.proxy.MapProxySupport.toData(MapProxySupport.java:1139)
 at com.hazelcast.map.impl.proxy.MapProxyImpl.put(MapProxyImpl.java:96)
 at com.hazelcast.map.impl.proxy.MapProxyImpl.put(MapProxyImpl.java:87)
 at org.compiere.util.CCache.put(CCache.java:302)
 at com.serunimobile.smilecore.model.MSMISGMMember.afterSave(MSMISGMMember.java:543)
 at org.compiere.model.PO.saveFinish(PO.java:2264)
 at org.compiere.model.PO.saveUpdate(PO.java:2415)
 at org.compiere.model.PO.save(PO.java:2156)