code: def listDevices(self, interface_id):
          
          LOG.debug("RPCFunctions.listDevices: interface_id = %s, _devices_raw = %s" % (
              interface_id, str(self._devices_raw)))
          remote = interface_id.split('-')[-1]
          if remote not in self._devices_raw:
              self._devices_raw[remote] = []
          if self.systemcallback:
              self.systemcallback('listDevices', interface_id)
          return self._devices_raw[remote]
docs: The CCU / Homegear asks for devices known to our XML-RPC server. We respond to that request using this method.