.F.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: testExpand (tester.ProblemTests)

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

Traceback (most recent call last):

  File ".../test.py", line 63, in testExpand

    self.assertEqual(Interval(-2, 11), i.expand(left=-1))

AssertionError: Interval(-2.0,11.0) != Interval(-2.0,10.0)



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

FAIL: testLeftRight (tester.ProblemTests)

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

Traceback (most recent call last):

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

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

AssertionError: -5.0 != '-5.0'



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

FAIL: testSum (tester.ProblemTests)

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

Traceback (most recent call last):

  File ".../test.py", line 105, in testSum

    self.assertRaises(ValueError, Interval.__add__, Interval(7, 99), Interval(101, 200))

AssertionError: ValueError not raised



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

Ran 16 tests in 0.006s



FAILED (failures=4)