phpunit assertion gotcha

phpunitAssertionsTest.php

<?php

class myClass
{
    public function __toString()
    {
        return "mememe";
    }
}

class TestCase extends PHPUnit_Framework_TestCase
{
    public function testAssertStringWithObject()
    {
        $class = new myClass();
        $this->assertEquals('mememe', $class);
    }

    public function testAssertStringWithSerialisedObject()
    {
        $class = new myClass();
        $this->assertEquals('mememe', "$class");
    }
}

$ phpunit testCaseTest.php 
PHPUnit 3.6.10 by Sebastian Bergmann.

..

Time: 1 second, Memory: 5.50Mb

OK (2 tests, 2 assertions)