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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_services_in_use(self):
 # type: () -> List[ServiceReference] """ Returns this bundle's ServiceReference list for all services it is using or an empty list. A bundle is considered to be using a service if its use count for that service is greater than zero. The list is valid at the time of the call to this method, however, as the Framework is a very dynamic environment, services can be modified or unregistered at any time. :return: An array of ServiceReference objects :raise BundleException: If the bundle has been uninstalled """

        if self._state == Bundle.UNINSTALLED:
            raise BundleException(
                "Can't call 'get_services_in_use' on an uninstalled bundle"
            )
        return self.__framework._registry.get_bundle_imported_services(self)