ruleBase.addPackage( pkg2 );
ruleBase = SerializationHelper.serializeObject( ruleBase );
final WorkingMemory workingMemory = ruleBase.newStatefulSession();
workingMemory.insert( new FirstClass() );
workingMemory.insert( new SecondClass() );
workingMemory.insert( new FirstClass.AlternativeKey() );
workingMemory.insert( new SecondClass.AlternativeKey() );
workingMemory.fireAllRules();