<?php

class MyClass
{
	private $prop = "teste";
	
    public function test()
    {
        $class = new class($this->prop) {

            public function __construct($prop)
            {
                $this->prop = $prop;
            }

            public function run() 
            {
                echo $this->prop, PHP_EOL;
            }

        };
        
        $class->run();
    }
}

$obj = new MyClass();
$obj->test();