def child():
     print 'Child started.'
     yield bluelet.null()
     print 'Child resumed.'
     yield bluelet.null()
     print 'Child ending.'
     yield bluelet.end(42)
 def parent():
     print 'Parent started.'
     yield bluelet.null()
     print 'Parent resumed.'
     result = yield child()
     print 'Child returned:', repr(result)
     print 'Parent ending.'
 def exc_child():
     yield bluelet.null()
     raise Exception()