code: func (g *Cloud) DeleteInstanceGroup(name string, zone string) error {
  	ctx, cancel := cloud.ContextWithCallTimeout()
  	defer cancel()
  
  	mc := newInstanceGroupMetricContext("delete", zone)
  	return mc.Observe(g.c.InstanceGroups().Delete(ctx, meta.ZonalKey(name, zone)))
  }
docs: // DeleteInstanceGroup deletes an instance group.