This appears to be problematic:

```python
class FeatureSerializer(DynamicFieldsSerializerMixin,
                        serializers.ModelSerializer):
    branches = BranchSerializer(many=True)

    class Meta:
        model = Feature
        fields = ('id', 'provider', 'feature_id', 'type', 'title', 'branches',
                  'project')
        read_only_fields = ('branches',)
```

yields:

    AssertionError: field 'branches' on serializer 'FeatureSerializer' specified in   
    `read_only_fields`, but also added as an explicit field.  Remove it from `read_only_fields`.