public function testAddSerializer()
 {
     $serializer = new DispatchingSerializer(array());
     $subSerializer = $this->getMock('Serializers\\DispatchableSerializer');
     $subSerializer->expects($this->any())->method('isSerializerFor')->will($this->returnValue(true));
     $subSerializer->expects($this->any())->method('serialize')->will($this->returnValue(42));
     $serializer->addSerializer($subSerializer);
     $this->assertEquals(42, $serializer->serialize(null));
 }