Sandbox JMS FactroyBean+.isSingleton() errors

[memelet]

For at least JmsConsumerFactoryBean and JmsProducerFactoryBean, the isSingleton() returns false, yet the getObject() seems to always return the same value.

Is this an error? I can't seem to find any unit tests for these classes.

Is this part of the sandbox intended to be included in 1.2?

[memelet]

On this same topic, I notice that very few classes actually extend AbstractFactoryBean, which is since 1.0.2. Is there a reason why this base class is little used?