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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(self):
 """ Start all the registered services. A new container is created for each service using the container class provided in the __init__ method. All containers are started concurrently and the method will block until all have completed their startup routine. """

        service_names = ', '.join(self.service_names)
        _log.info('starting services: %s', service_names)

        SpawningProxy(self.containers).start()

        _log.debug('services started: %s', service_names)