add test to show how it works a bit more
diff --git a/testing/resources/top_sorted_json.json b/testing/resources/top_sorted_json.json
new file mode 100644
index 0000000..62083e7
--- /dev/null
+++ b/testing/resources/top_sorted_json.json
@@ -0,0 +1,16 @@
+{
+  "01-alist": [
+    2,
+    34,
+    234
+  ],
+  "alist": [
+    2,
+    34,
+    234
+  ],
+  "00-foo": "bar",
+  "02-blah": null,
+  "blah": null,
+  "foo": "bar"
+}
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