Setting process parent is giving errors.

[maxrunner]

So i want do define a parent and child for two processes,

procInst=this.jbpmCtx.getProcessInstance(pd,processParentKey);
procInstSon=this.jbpmCtx.getProcessInstance(pd,processSonKey);

procInstSon.getRootToken().setParent(procInst.getRootToken());
this.jbpmCtx.save(procInstSon);
this.jbpmCtx.save(procInst);

this makes the parent process mad, when i try to view its tokens in the console here's the problem:

Error listing token instances: An exception of type "org.hibernate.HibernateException" was thrown. The message is: null index column for collection: org.jbpm.graph.exe.Token.children

this happens because the subprocess token has no name.....

[maxrunner]

Edit: Forgot to say, that the token class has no setName....:(