Ensuring correct schema for zero-rows output. Adding comment for bug ID

Author: Saumitra Shahapure

pandas/io/tests/test_gbq.py

@@ -297,9 +297,10 @@ def test_download_dataset_larger_than_200k_rows(self):
         self.assertEqual(len(df.drop_duplicates()), 200005)
 
     def test_zero_rows(self):
-        df = gbq.read_gbq("SELECT * FROM [publicdata:samples.wikipedia] where timestamp=-9999999", project_id=PROJECT_ID)
-        tm.assertIs(df, DataFrame, "Zero rows result should be dataframe.")
-        self.assertEqual(len(df), 0)
+        # Bug fix for https://github.com/pydata/pandas/issues/10273
+        df = gbq.read_gbq("SELECT title, language  FROM [publicdata:samples.wikipedia] where timestamp=-9999999", project_id=PROJECT_ID)
+        expected_result = DataFrame(columns=['title', 'language'])
+        self.assert_frame_equal(df, expected_result)
 
 
 class TestToGBQIntegration(tm.TestCase):