......FF..F...F.

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

FAIL: testIntersect (tester.ProblemTests)

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

Traceback (most recent call last):

  File ".../test.py", line 68, in testIntersect

    self.assertEqual(Interval(6, 11), Interval(None, 11).intersect(Interval(6, 12)))

AssertionError: Interval(6.0, 11.0) != Interval(None, 11.0)



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

FAIL: testIntersects (tester.ProblemTests)

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

Traceback (most recent call last):

  File ".../test.py", line 75, in testIntersects

    self.assertFalse(Interval(None, -33).intersects(Interval(-32, 4)))

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 102, in testSum

    self.assertEqual(Interval(None, None), Interval(None, 11) + Interval(10, None))

AssertionError: Interval(None, None) != Interval(10.0, 11.0)



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

Ran 16 tests in 0.006s



FAILED (failures=4)