PHP Composer PSR-4自动加载和子命名空间，类未找到

这个问题是独立的，但我之前确实问过一个类似的问题:-

编者给出错误，"类未找到"

问题已解决，但我未能解释嵌套问题。我想提出一个新问题会更合适。

我搜索了很多，但我不能使嵌套命名空间与psr-4自动加载工作。

目录结构:-

│   composer.json
│   run.php
│
├───src
│   ├───one
│   │       parentclass.php
│   │
│   └───two
│           childclass.php
│
└───vendor
    │   autoload.php
    │
    └───composer
            autoload_classmap.php
            autoload_namespaces.php
            autoload_psr4.php
            autoload_real.php
            ClassLoader.php
            installed.json
            LICENSE

parentclass.php: -

<?php
namespace myns'one;
abstract class parentclass
{
    abstract public function abc();
}

childclass.php: -

namespace myns'two;
namespace myns'one;
use myns'one'parentclass as parentclass;
class childclass extends parentclass
{
    public function abc()
    {
        echo 'hello world';
    }
}

composer.json: -

{
    "name": "myvendor/mypackage",
    "description": "nothing",
    "authors": [
        {
            "name": "Omar Tariq",
            "email": "XXXXX@gmail.com"
        }
    ],
    "require": {},
    "autoload": {
        "psr-4": {
            "myns''": "src/",
            "myns''one''": "src/one/",
            "myns''two''": "src/two/"
        }
    }
}

run.php: -

<?php
require_once __DIR__ . '/vendor/autoload.php';
use myns'two'childclass as childclass;
$childclass = new childclass();
$childclass->abc();

当我运行php run.php。它给出错误:-

Fatal error: Class 'myns'two'childclass' not found in C:'wamp'...'run.php on line 7