}
	if len(permissions) == 0 {
		return nil, fmt.Errorf("must have at least 1 permission")
	}

	var principals []*rbacpb.Principal
	for _, rl := range m.principals {
		principal, err := generatePrincipal(rl, forTCP, useAuthenticated, action)
		if err != nil {
			return nil, err
		}
		principals = append(principals, principal)
	}
	if len(principals) == 0 {