def testFilter (self): self.assertEquals (Nil, Nil.filter (lambda x: True)) self.assertEquals (List (2, 4), List (1, 2, 3, 4, 5).filter (_ % 2 == 0)) self.assertEquals (Nil, List (1, 2, 3, 4, 5).filter (_ > 10)) self.assertEquals (List, List (1, 2, 3, 4, 5).filter (lambda x: x > 10).__class__) pass