code: def _prepair(self):
          '''Try to connect to the given dbus services. If successful it will
          return a callable dbus proxy and those arguments.
          '''
          try:
              sessionbus = dbus.SessionBus()
              systembus  = dbus.SystemBus()
          except:
              return (None, None)
          for dbus_props in self.DBUS_SHUTDOWN.values():
              try:
                  if dbus_props['bus'] == SESSION_BUS:
                      bus = sessionbus
                  else:
                      bus = systembus
                  interface = bus.get_object(dbus_props['service'],
                                             dbus_props['objectPath'])
                  proxy = interface.get_dbus_method(dbus_props['method'],
                                                    dbus_props['interface'])
                  return (proxy, dbus_props['arguments'])
              except dbus.exceptions.DBusException:
                  continue
          return (None, Nonef _prepair(self):
          '''Try to connect to the given dbus services. If successful it will
          return a callable dbus proxy and those arguments.
          '''
          try:
              sessionbus = dbus.SessionBus()
              systembus  = dbus.SystemBus()
          except:
              return (None, None)
          for dbus_props in self.DBUS_SHUTDOWN.values():
              try:
                  if dbus_props['bus'] == SESSION_BUS:
                      bus = sessionbus
                  else:
                      bus = systembus
                  interface = bus.get_object(dbus_props['service'],
                                             dbus_props['objectPath'])
                  proxy = interface.get_dbus_method(dbus_props['method'],
                                                    dbus_props['interface'])
                  return (proxy, dbus_props['arguments'])
              except dbus.exceptions.DBusException:
                  continue
          return (None, None)
docs: Try to connect to the given dbus services. If successful it will
          return a callable dbus proxy and those arguments.