fixup! Do not lazy load forward relations

Author: Tim Csitkovics

rest_framework_json_api/serializers.py

@@ -185,7 +185,9 @@ def to_representation(self, instance):
                 context = getattr(self, '_context', {})
                 request = getattr(context.get('request', None), '_request', None)
                 is_included = request is not None and field.source in getattr(request, 'GET', None)
-                if not is_included and isinstance(field, ModelSerializer) and hasattr(instance, field.source + "_id"):
+                if not is_included \
+                        and isinstance(field, ModelSerializer) \
+                        and hasattr(instance, field.source + "_id"):
                     attribute = getattr(instance, field.source + "_id")
                     if attribute is None:
                         ret[field.field_name] = None