code: func Init(dc driverapi.DriverCallback, config map[string]interface{}) error {
  	var err error
  	c := driverapi.Capability{
  		DataScope:         datastore.GlobalScope,
  		ConnectivityScope: datastore.GlobalScope,
  	}
  
  	d := &driver{
  		networks: networkTable{},
  		config:   config,
  	}
  
  	d.vxlanIdm, err = idm.New(nil, "vxlan-id", 0, vxlanIDEnd)
  	if err != nil {
  		return fmt.Errorf("failed to initialize vxlan id manager: %v", err)
  	}
  
  	return dc.RegisterDriver(networkType, d, c)
  }
docs: // Init registers a new instance of overlay driver