....E....E.E....

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

ERROR: testHash (tester.ProblemTests)

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Traceback (most recent call last):

  File ".../test.py", line 92, in testHash

    self.assertEqual(hash(Interval(3, 11)), hash(Interval(3, 11)))

TypeError: unhashable instance



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

ERROR: testLeftRight (tester.ProblemTests)

----------------------------------------------------------------------

Traceback (most recent call last):

  File ".../test.py", line 57, in testLeftRight

    self.assertEqual(-5.0, i.left())

TypeError: 'float' object is not callable



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

ERROR: testOpen (tester.ProblemTests)

----------------------------------------------------------------------

Traceback (most recent call last):

  File ".../test.py", line 49, in testOpen

    self.assertFalse(i.open())

AttributeError: Interval instance has no attribute 'open'



----------------------------------------------------------------------

Ran 16 tests in 0.005s



FAILED (errors=3)