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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 get_subscribed_services_names(cls):
 """Get a list of the names of all subscribed music services. Returns: list: A list of strings. """

        # This is very inefficient - loops within loops within loops, and
        # many network requests
        # Optimise it?
        accounts_for_service = Account.get_accounts_for_service
        service_data = cls._get_music_services_data().values()
        return [
            service['Name'] for service in service_data
            if len(
                accounts_for_service(service['ServiceType'])
            ) > 0
        ]