autoflake: remove unused imports and statements

polymorphic/admin/childadmin.py

@@ -8,13 +8,11 @@ from django.core.urlresolvers import resolve
 from django.utils import six
 from django.utils.translation import ugettext_lazy as _
 
-from .helpers import PolymorphicInlineSupportMixin
 from ..admin import PolymorphicParentModelAdmin
 
 
 class ParentAdminNotRegistered(RuntimeError):
     "The admin site for the model is not registered."
-    pass
 
 
 class PolymorphicChildModelAdmin(admin.ModelAdmin):

polymorphic/admin/parentadmin.py

@@ -34,12 +34,10 @@ if sys.version_info[0] >= 3:
 
 class RegistrationClosed(RuntimeError):
     "The admin model can't be registered anymore at this point."
-    pass
 
 
 class ChildAdminNotRegistered(RuntimeError):
     "The admin site for the model is not registered."
-    pass
 
 
 class PolymorphicParentModelAdmin(admin.ModelAdmin):