if !strings.HasSuffix(ret.host, ":443") {
		ret.host += ":443"
	}
	const projSeg = "/projects/"
	i := strings.Index(u.Path, projSeg)
	if i == -1 {
		return nil, fmt.Errorf("webhook URL %s doesn't contain the projects segment", u)
	}
	i += len(projSeg)
	j := strings.IndexByte(u.Path[i:], '/')
	if j == -1 {
		return nil, fmt.Errorf("webhook URL %s is malformed", u)
	}
	ret.gcpProject = u.Path[i : i+j]

	if err != nil {
		return err
	}
	for k, v := range ret {
		if !strings.EqualFold(k, "authorization") {
			if _, ok := dst[k]; ok {
				return fmt.Errorf("underlying %s credentials contain a %s header which is already present in the combined credentials", kind, k)
			}
			dst[k] = v
		} else {
			dst[dstHdr] = v
		}
	}
	return nil
}

type hubMembership struct {