public function testCanBeCastedIntoAString()
{
$value = new UniqueValue('', 'foo');
$this->assertEquals('(unique) \'foo\'', (string) $value);
$value = new UniqueValue('', new \stdClass());
$this->assertEquals("(unique) stdClass::__set_state(array(\n))", (string) $value);
$value = new UniqueValue('', new DummyValue('foo'));
$this->assertEquals('(unique) foo', (string) $value);
}