public function testUnserialize()
 {
     $snak = new PropertyValueSnak(new PropertyId('P1'), new StringValue('a'));
     $snak->unserialize('a:2:{i:0;i:2;i:1;C:22:"DataValues\\StringValue":1:{b}}');
     $expected = new PropertyValueSnak(new PropertyId('P2'), new StringValue('b'));
     $this->assertTrue($snak->equals($expected));
 }