old_contents: from django.contrib import admin
  from cropimg.fields import CIImageField
  from cropimg.widgets import CIImgWidget
  from .models import SimpleModel
  
  
  class CIAdminMixin(object):
  
      def formfield_for_dbfield(self, db_field, **kwargs):
          form_field = super(CIAdminMixin, self).formfield_for_dbfield(db_field, **kwargs)
          if isinstance(db_field, CIImageField):
              form_field.widget = CIImgWidget()
          return form_field
  
  
new_contents: from cropimg.fields import CIImageField
  from cropimg.widgets import CIImgWidget
  
  
  class CIAdminMixin(object):
  
      def formfield_for_dbfield(self, db_field, **kwargs):
          form_field = super(CIAdminMixin, self).formfield_for_dbfield(db_field, **kwargs)
          if isinstance(db_field, CIImageField):
              form_field.widget = CIImgWidget()
          return form_field
  
  
subject: Remove irrelevant imports