code: func (g *Cloud) GetRegionalBackendServiceHealth(name, region string, instanceGroupLink string) (*compute.BackendServiceGroupHealth, error) {
  	ctx, cancel := cloud.ContextWithCallTimeout()
  	defer cancel()
  
  	mc := newBackendServiceMetricContext("get_health", region)
  	ref := &compute.ResourceGroupReference{Group: instanceGroupLink}
  	v, err := g.c.RegionBackendServices().GetHealth(ctx, meta.RegionalKey(name, region), ref)
  	return v, mc.Observe(err)
  }
docs: // GetRegionalBackendServiceHealth returns the health of the BackendService
  // identified by the given name, in the given instanceGroup. The
  // instanceGroupLink is the fully qualified self link of an instance group.