remove unnecessary test

Author: Ben Kandel

pandas/io/tests/parser/common.py

@@ -611,11 +611,8 @@ def test_multi_index_blank_df(self):
         data = """a,b
 """
         df = self.read_csv(StringIO(data), header=[0])
-        expected = DataFrame(columns=[('a'), ('b')])
+        expected = DataFrame(columns=[('a',), ('b',)])
         tm.assert_frame_equal(df, expected)
-        expected_csv = expected.to_csv()
-        round_trip = self.read_csv(StringIO(expected_csv))
-        tm.assert_frame_equal(expected, round_trip)
 
         data_multiline = """a,b
 c,d