Fix linter

Author: WaVEV

tests/model_fields_/test_embedded_model.py

@@ -18,16 +18,11 @@
 from django_mongodb_backend.models import EmbeddedModel
 
 from .models import (
-    A,
     Address,
     ArtifactDetail,
     Author,
-    B,
     Book,
-    C,
-    D,
     Data,
-    E,
     ExhibitSection,
     Holder,
     Library,