public function testSerialization()
{
$function1 = $this->internalFunction();
$this->assertEquals($function1, unserialize(serialize($function1)));
$function2 = $this->emptyFunction();
$this->assertEquals($function2, unserialize(serialize($function2)));
$function3 = $this->functionWithReturnStatement();
$this->assertEquals($function3, unserialize(serialize($function3)));
}