code: async function routeSet(target, netInterface, rootPwd) {
      const connName = await searchConnNameFromNetworkInterface(netInterface);
      const prevRoutes = await searchPrevRoutes(target);
      if (prevRoutes.length == 1) {
          if (prevRoutes[0].connName === connName &&
              prevRoutes[0].target === target &&
              prevRoutes[0].gatewayIP === '0.0.0.0') {
              return; // no need to do anything
          }
      }
      await routeDelete(target, rootPwd);
  
      const cmds = [
          ['nmcli', 'connection', 'modify', connName,
              '+ipv4.routes', `${target} 0.0.0.0`],
          ['nmcli', 'connection', 'down', connName],
          ['nmcli', 'connection', 'up', connName],
      ];
      return await executeCommands(cmds, null, {sudo: true, password: rootPwd});
  }
docs: Set static route to ipv4 network
  @param {string} target : the destination network or host. e.g. 224.0.23.0/32
  @param {string} netInterface : network interface to set route
  @param {string} rootPwd : root password for executing sudo
  @return {Promise} Return last command output