code: func (g *Cloud) ListRegionForwardingRules(region string) ([]*compute.ForwardingRule, error) {
  	ctx, cancel := cloud.ContextWithCallTimeout()
  	defer cancel()
  
  	mc := newForwardingRuleMetricContext("list", region)
  	v, err := g.c.ForwardingRules().List(ctx, region, filter.None)
  	return v, mc.Observe(err)
  }
docs: // ListRegionForwardingRules lists all RegionalForwardingRules in the project & region.