[Twisted-Python] Unit test

Short question, which is the adecuate way of doing unit test of a sequence of defered events ? one chained to the other. If each deferred need a callback method, I have already more that thirty functiones defined, and each time I need more. How to do it ? defered = something <the magic> defered = the_next_thing # that need the previous defered to have been acomplished etc... I can imagine various tricks, but I supose there is a standart way. Thanks. RodrigoB.