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