code: def getNameOwner(self, busName):
          
          d = self.callRemote(
              '/org/freedesktop/DBus',
              'GetNameOwner',
              interface='org.freedesktop.DBus',
              signature='s',
              body=[busName],
              destination='org.freedesktop.DBus',
          )
          return d
docs: Calls org.freedesktop.DBus.GetNameOwner
          @rtype: L{twisted.internet.defer.Deferred}
          @returns: a Deferred to the unique connection name owning the bus name