...F.

======================================================================

FAIL: test_songs_by_tags (tester.ProblemTests)

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Traceback (most recent call last):

  File ".../test.py", line 53, in test_songs_by_tags

    self.assertNoOrder([('Right Turn', 'Alice In Chains')], songs_by_tags('cornell', 'staley'))

  File ".../test.py", line 35, in assertNoOrder

    self.assertEqual(set(first), set(second))

AssertionError: set([('Right Turn', 'Alice In Chains')]) != set([])



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Ran 5 tests in 0.001s



FAILED (failures=1)