code: func (plugin *cniNetworkPlugin) Event(name string, details map[string]interface{}) {
  	if name != network.NET_PLUGIN_EVENT_POD_CIDR_CHANGE {
  		return
  	}
  
  	plugin.Lock()
  	defer plugin.Unlock()
  
  	podCIDR, ok := details[network.NET_PLUGIN_EVENT_POD_CIDR_CHANGE_DETAIL_CIDR].(string)
  	if !ok {
  		klog.Warningf("%s event didn't contain pod CIDR", network.NET_PLUGIN_EVENT_POD_CIDR_CHANGE)
  		return
  	}
  
  	if plugin.podCidr != "" {
  		klog.Warningf("Ignoring subsequent pod CIDR update to %s", podCIDR)
  		return
  	}
  
  	plugin.podCidr = podCIDR
  }
docs: // Event handles any change events. The only event ever sent is the PodCIDR change.
  // No network plugins support changing an already-set PodCIDR