code: func (tx *Transaction) AddBridge(properties ...string) {
  	args := []string{"--if-exists", "del-br", tx.bridge, "--", "add-br", tx.bridge}
  	if len(properties) > 0 {
  		args = append(args, "--", "set", "Bridge", tx.bridge)
  		args = append(args, properties...)
  	}
  	tx.vsctlExec(args...)
  }
docs: // AddBridge creates the bridge associated with the transaction, optionally setting
  // properties on it (as with "ovs-vsctl set Bridge ..."). If the bridge already
  // existed, it will be destroyed and recreated.