code: func (g *Cloud) ListNetworkEndpointGroup(zone string) ([]*computebeta.NetworkEndpointGroup, error) {
  	ctx, cancel := cloud.ContextWithCallTimeout()
  	defer cancel()
  
  	mc := newNetworkEndpointGroupMetricContext("list", zone)
  	negs, err := g.c.BetaNetworkEndpointGroups().List(ctx, zone, filter.None)
  	return negs, mc.Observe(err)
  }
docs: // ListNetworkEndpointGroup returns the collection of network endpoints for the zone