vsphere/host_network_system_helper.go
func hostNetworkSystemFromHostSystem(hs *object.HostSystem) (*object.HostNetworkSystem, error) {
	ctx, cancel := context.WithTimeout(context.Background(), defaultAPITimeout)
	defer cancel()
	return hs.ConfigManager().NetworkSystem(ctx)
}
func hostNetworkSystemFromHostSystem(hs *object.HostSystem) (*object.HostNetworkSystem, error) {
	ctx, cancel := context.WithTimeout(context.Background(), defaultAPITimeout)
	defer cancel()
	return hs.ConfigManager().NetworkSystem(ctx)
}
// hostNetworkSystemFromHostSystem locates a HostNetworkSystem from a specified
// HostSystem.