          ]
          self.assertEquals(serializer.data, expected)
  
      def test_many_to_many_update(self):
          data = {'id': 1, 'name': u'source-1', 'targets': [1, 2, 3]}
          instance = ManyToManySource.objects.get(pk=1)
          serializer = ManyToManySourceSerializer(instance, data=data)
          self.assertTrue(serializer.is_valid())
          self.assertEquals(serializer.data, data)
          serializer.save()
 
</s> remove         data = {'id': 1, 'name': u'source-1', 'target': 2}
 </s> add         data = {'id': 1, 'name': 'source-1', 'target': 2} </s> remove         data = {'id': 1, 'name': u'target-1', 'sources': [1]}
 </s> add         data = {'id': 1, 'name': 'target-1', 'sources': [1]} </s> remove         data = {'id': 4, 'name': u'target-4', 'sources': [1, 3]}
 </s> add         data = {'id': 4, 'name': 'target-4', 'sources': [1, 3]} </s> remove                 {'id': 1, 'name': u'source-1', 'targets': [1]},
                {'id': 2, 'name': u'source-2', 'targets': [1, 2]},
                {'id': 3, 'name': u'source-3', 'targets': [1, 2, 3]}
 </s> add                 {'id': 1, 'name': 'source-1', 'targets': [1]},
                {'id': 2, 'name': 'source-2', 'targets': [1, 2]},
                {'id': 3, 'name': 'source-3', 'targets': [1, 2, 3]} </s> remove                 {'id': 1, 'name': u'source-1', 'targets': [1, 2, 3]},
                {'id': 2, 'name': u'source-2', 'targets': [1, 2]},
                {'id': 3, 'name': u'source-3', 'targets': [1, 2, 3]}
 </s> add                 {'id': 1, 'name': 'source-1', 'targets': [1, 2, 3]},
                {'id': 2, 'name': 'source-2', 'targets': [1, 2]},
                {'id': 3, 'name': 'source-3', 'targets': [1, 2, 3]}
        data = {'id': 1, 'name': 'source-1', 'targets': [1, 2, 3]}
          ]
          self.assertEquals(serializer.data, expected)
  
      def test_many_to_many_update(self):
        data = {'id': 1, 'name': 'source-1', 'targets': [1, 2, 3]}
          instance = ManyToManySource.objects.get(pk=1)
          serializer = ManyToManySourceSerializer(instance, data=data)
          self.assertTrue(serializer.is_valid())
          self.assertEquals(serializer.data, data)
          serializer.save()
keep keep keep keep replace keep keep keep keep keep
 First passing test under p3k \o/ 
rest_framework/tests/pk_relations.py