new_contents: __author__ = 'Nino Bašić <nino.basic@fmf.uni-lj.si>'
  
  import unittest
  from revolver import Revolver
  
  
  class RevolverTest(unittest.TestCase):
  
      def test_iter(self):
          r = Revolver([[1], [20, 10], [300, 200, 100]])
          self.assertIs(r, iter(r))
  
      def test_revolver_1(self):
          r = Revolver([[1], [20, 10], [300, 200, 100]])
          vrstni_red = [1, 10, 100, 20, 200, 300]
          for x in vrstni_red:
              self.assertEqual(x, next(r))
          with self.assertRaises(StopIteration):
              next(r)
  
      def test_revolver_2(self):
          r = Revolver([[1], [2], [3], [4], [5]])
          vrstni_red = [1, 2, 3, 4, 5]
          for x in vrstni_red:
              self.assertEqual(x, next(r))
          with self.assertRaises(StopIteration):
              next(r)
  
      def test_revolver_3(self):
          r = Revolver([[], [10, 20], [], [], []])
          vrstni_red = [20, 10]
          for x in vrstni_red:
              self.assertEqual(x, next(r))
          with self.assertRaises(StopIteration):
              next(r)
  
      def test_revolver_4(self):
          r = Revolver([[], [], [], [], []])
          with self.assertRaises(StopIteration):
              next(r)
  
      def test_revolver_5(self):
          r = Revolver([[10, 20, 30, 40, 50, 60, 70]])
          vrstni_red = [70, 60, 50, 40, 30, 20, 10]
          for x in vrstni_red:
              self.assertEqual(x, next(r))
          with self.assertRaises(StopIteration):
              next(r)
  
      def test_revolver_6(self):
          r = Revolver([[10, 20, 30], [], [400, 500, 600], [], [2000, 3000, 4000]])
          vrstni_red = [30, 600, 4000, 20, 500, 3000, 10, 400, 2000]
          for x in vrstni_red:
              self.assertEqual(x, next(r))
          with self.assertRaises(StopIteration):
              next(r)
  
  
  if __name__ == '__main__':
      unittest.main()
  
subject: Add unittest for Task 3