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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 getNameOwner(self, busName):
 """ Calls org.freedesktop.DBus.GetNameOwner @rtype: L{twisted.internet.defer.Deferred} @returns: a Deferred to the unique connection name owning the bus name """

        d = self.callRemote(
            '/org/freedesktop/DBus',
            'GetNameOwner',
            interface='org.freedesktop.DBus',
            signature='s',
            body=[busName],
            destination='org.freedesktop.DBus',
        )
        return d