使用 Dingo+Laravel-modules 时调用的接口版本是最后一个无法指定版本接口?

路由

<?php

$api = app('Dingo\Api\Routing\Router');

$api->version('v1', function ($api) {
    Route::group(['middleware' => 'api', 'prefix' => 'testapi', 'namespace' => 'Modules\TestApi\Http\V1\Controllers'], function($api)
    {
        $api->get('/version', function(){
            return 'this is Modules routes version 1';
        });
    });

});

$api->version('v2', function ($api) {
    Route::group(['middleware' => 'api', 'prefix' => 'testapi', 'namespace' => 'Modules\TestApi\Http\V2\Controllers'], function($api)
    {
        $api->get('/version', function(){
            return 'this is Modules routes version 2';
        });
    });

});

Accept:application/vnd.myapp.v1+json

以GET的请求: http://myhost/testapi/version

回显信息为: this is Modules routes version 2

期望显示的信息应该是: this is Modules routes version 1