Adding a new import and alphabetizing them (OCD, I know)

editor/templatetags/admin_tree_list.py

@@ -1,12 +1,12 @@
-from django.contrib.admin.templatetags.admin_list import result_headers
+from django.db import models
 from django.template import Library
-from django.core.exceptions import ObjectDoesNotExist
+from django.contrib.admin.templatetags.admin_list import result_headers
 from django.contrib.admin.util import lookup_field, display_for_field, label_for_field
+from django.contrib.admin.views.main import EMPTY_CHANGELIST_VALUE
+from django.core.exceptions import ObjectDoesNotExist
 from django.utils.encoding import smart_unicode, force_unicode
-from django.utils.safestring import mark_safe
 from django.utils.html import escape, conditional_escape
-from django.db import models
-
+from django.utils.safestring import mark_safe
 
 register = Library()