PHP package-private class members

src\MyInternalStuff\myNonPublicWidget.php

<?php
package MyVendor\MyLibrary // acts same as `namespace` but changes all classes into package-private
{
    namespace MyInternalStuff // cause current namespace would be MyVendor\MyLibrary\MyInternalStuff
    {
        class MyNonPublicWidget // class name would be MyVendor\MyLibrary\MyInternalStuff\MyNonPublicWidget
        {
    
        }
    }
}

src\PublicApi.alternative.php

<?php
package MyVendor\MyLibrary
{
    namespace // missing name cause class ns woul be MyVendor\MyLibrary
    {
        public class PublicApi // any package class need to be public prefixed for visibility in lower level namespaces (out of package namespace)
        {
            private $widget;
        
            public function __construct()
            {
                $this->widget = new MyInternalStuff\MyNonPublicWidget();
            }
        }
    }
}

src\PublicApi.php

<?php
package MyVendor\MyLibrary; // acts same as `namespace` but changes all classes into package-private

public class PublicApi // as of we are in package we need to set public visibility in packag lower namespaces
{
    private $widget;

    public function __construct()
    {
        $this->widget = new MyInternalStuff\MyNonPublicWidget();
    }
}

The namespace keyword if not providing any name inside package declaration is optional, so provided with missing name has no effect.