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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def start_class(self, class_):
 """ Start all services of a given class. If this manager doesn't already have a service of that class, it constructs one and starts it. """

        matches = filter(lambda svc: isinstance(svc, class_), self)
        if not matches:
            svc = class_()
            self.register(svc)
            matches = [svc]
        map(self.start, matches)
        return matches