code: func (gce *Cloud) ListTargetHTTPProxies() (*compute.TargetHttpProxyList, error) {
  	// TODO: use PageToken to list all not just the first 500
  	return gce.service.TargetHttpProxies.List(gce.projectID).Do()
  }
docs: // ListTargetHTTPProxies lists all TargetHTTPProxies in the project.