add test to show how it works a bit more
diff --git a/tests/pretty_format_json_test.py b/tests/pretty_format_json_test.py
index 72c2b86..7bfc31f 100644
--- a/tests/pretty_format_json_test.py
+++ b/tests/pretty_format_json_test.py
@@ -75,6 +75,11 @@
     assert ret == 1
 
 
+def test_top_sorted_get_pretty_format():
+    ret = pretty_format_json(['--top-keys=01-alist,alist', get_resource_path('top_sorted_json.json')])
+    assert ret == 0
+
+
 def test_badfile_pretty_format_json():
     ret = pretty_format_json([get_resource_path('ok_yaml.yaml')])
     assert ret == 1