func: static void migrate_set_downtime(QTestState *who, const char *value)
  
  {
  
      QDict *rsp;
  
      gchar *cmd;
  
  
  
      cmd = g_strdup_printf("{ 'execute': 'migrate_set_downtime',"
  
                            "'arguments': { 'value': %s } }", value);
  
      rsp = qtest_qmp(who, cmd);
  
      g_free(cmd);
  
      g_assert(qdict_haskey(rsp, "return"));
  
      QDECREF(rsp);
  
  }
  