Don't bend over backward to avoid passing empty .

Addresses: #742 (comment)

Author: tseaver

gcloud/pubsub/api.py

@@ -51,7 +51,4 @@ def list_topics(page_size=None, page_token=None,
         params['pageToken'] = page_token
 
     path = '/projects/%s/topics' % project
-    if params:
-        return connection.api_request(method='GET', path=path,
-                                      query_params=params)
-    return connection.api_request(method='GET', path=path)
+    return connection.api_request(method='GET', path=path, query_params=params)

gcloud/pubsub/test_api.py

@@ -37,7 +37,7 @@ def test_w_explicit_connection_no_paging(self):
         req = conn._requested[0]
         self.assertEqual(req['method'], 'GET')
         self.assertEqual(req['path'], '/projects/%s/topics' % PROJECT)
-        self.assertEqual(req.get('query_params'), None)
+        self.assertEqual(req['query_params'], {})
 
     def test_w_explicit_connection_w_paging(self):
         TOPIC_NAME = 'topic_name'