docs: @BetaApi
    public final ListTargetVpnGatewaysPagedResponse listTargetVpnGateways(ProjectRegionName region) {
      ListTargetVpnGatewaysHttpRequest request =
          ListTargetVpnGatewaysHttpRequest.newBuilder()
              .setRegion(region == null ? null : region.toString())
              .build();
      return listTargetVpnGateways(request);
    }