Will attach test case.

MapA (Foaf.PERSON -> ClassA)
MapB(Foaf.PERSON -> ClassB)

Use beansession with ONLY mapA to register a bean and save the beansession. Now use triples generated with a new beansession with ONLY mapB and following exception is thrown

Exception in thread "main" org.tupeloproject.kernel.OperatorException: Error:
at org.tupeloproject.kernel.BeanSession.fetchBean(BeanSession.java:468)
at MultiMap.read(MultiMap.java:51)
at MultiMap.main(MultiMap.java:60)
Caused by: java.lang.IllegalArgumentException: unkown rdf type for bean"MultiMap$BeanA"
at org.tupeloproject.kernel.BeanSession.register(BeanSession.java:632)
at org.tupeloproject.kernel.beans.AbstractBeanCodec.fetchBean(AbstractBeanCodec.java:241)
at org.tupeloproject.kernel.beans.AbstractBeanCodec.fetchBean(AbstractBeanCodec.java:176)
at org.tupeloproject.kernel.beans.BeanCodecManager.fetchBean(BeanCodecManager.java:115)
at org.tupeloproject.kernel.BeanSession.fetchBean(BeanSession.java:490)
at org.tupeloproject.kernel.BeanSession.fetchBean(BeanSession.java:466)
... 2 more

This is list of triples:
<tag:tupeloproject.org,2006:ba8cdf2896878f85a2cb8056270ce65519506c3b> <tag:tupeloproject.org,2006:/2.0/beans/2.0/propertyImplementationRdfType> <http://xmlns.com/foaf/0.1/Person> .
<tag:tupeloproject.org,2006:ba8cdf2896878f85a2cb8056270ce65519506c3b> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://xmlns.com/foaf/0.1/Person> .
<tag:tupeloproject.org,2006:ba8cdf2896878f85a2cb8056270ce65519506c3b> <tag:tupeloproject.org,2006:/2.0/beans/2.0/propertyValueImplementationClassName> "MultiMap$BeanA" .
<tag:tupeloproject.org,2006:ba8cdf2896878f85a2cb8056270ce65519506c3b> <http://xmlns.com/foaf/0.1/name> "Hello" .
<tag:tupeloproject.org,2006:ba8cdf2896878f85a2cb8056270ce65519506c3b> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <tag:tupeloproject.org,2006:/2.0/beans/2.0/storageTypeBeanEntry> .