title: Unit testing nested subflows (subflows of subflows)
body: <p>I'm trying to write unit test for a flow, which has subflow, which, itself, has another subflow.</p>
  
  <p>I register first flow using
  <code>FlowDefinitionResource getResource(FlowDefinitionResourceFactory resourceFactory)</code>.</p>
  
  <p>Then I register subflow definitions during test execution in <code>FlowDefinitionRegistry</code> before transitioning to them.</p>
  
  <p>Transitioning to "first level" subflow goes ok. The result of transitioning to subflow of current subflow - <code>NoSuchFlowDefinitionException</code>.</p>
  
  <p>The problem is that subflow definitions are all seem attached to the primary flow of the test and subflow can't be found within another subflow.</p>
  
  <p>Is there any way to attach subflow definition to another subflow in tests, which extend <code>AbstractXmlFlowExecutionTests</code>?</p>