PHPUnit::How can be __construct with protected variables tested?

PhpUnit::How can be __construct with protected variables tested?

(not always we should add public method getVal()- soo without add method that return protected variable value)

Example:

  class Example{
    protected $_val=null;
    function __construct($val){
      $this->_val=md5 ($val);
    }
   }

Edit:

also exist problem to test in function that return void

Edit2:

Example why we need test __construct:

class Example{
        protected $_val=null;
       //user write _constract instead __construct
        function _constract($val){
          $this->_val=md5 ($val);
        }

       function getLen($value){
         return strlen($value);
       }
 }

 class ExampleTest extends PHPUnit_Framework_TestCase{
     test_getLen(){
       $ob=new Example();//call to __construct and not to _constract
        $this->assertEquals( $ob->getLen('1234'), 4);
     }
 }

test run ok, but Example class "constructor" wasn't created!

Thanks