.F........F...F.

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

FAIL: testContains (tester.ProblemTests)

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

Traceback (most recent call last):

  File ".../test.py", line 85, in testContains

    self.assertFalse(Interval(None, -8).contains(Interval(-8, None)))

AssertionError



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

FAIL: testLen (tester.ProblemTests)

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

Traceback (most recent call last):

  File ".../test.py", line 99, in testLen

    self.assertEqual(7, len(Interval(-2, 4.1)))

AssertionError: 7 != 6



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

FAIL: testSum (tester.ProblemTests)

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

Traceback (most recent call last):

  File ".../test.py", line 104, in testSum

    self.assertEqual(Interval(6, 99), Interval(6, 97) + Interval(7, 99.0))

AssertionError: Interval(6.0, 99.0) != Interval(6.0, 0.0)



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

Ran 16 tests in 0.005s



FAILED (failures=3)