text: import unittest
  
  from dcp.problems.linkedlist.single import build_list
  from dcp.problems.linkedlist.rev_sum import rev_sum1
  
  class Test_ReverseSum1(unittest.TestCase):
      
      def setUp(self):
          pass
  
      def test_case1(self):
  
          assert rev_sum1(None, None) == None
  
      def test_case2(self):
          
          n1, n2 = build_list([7, 1, 6]), build_list([5, 9, 3])
  
          actual = rev_sum1(n1, n2)
  
          expected = build_list([1, 0, 1, 2])
          
          assert actual == expected
          
      def test_case3(self):
          
          n1, n2 = build_list([7, 1, 6]), build_list([5, 9, 2])
  
          actual = rev_sum1(n1, n2)
  
          expected = build_list([9, 1 , 2])
          
          assert actual == expected
  
      def test_case4(self):
          
          n1, n2 = build_list([1]), build_list([1])
  
          actual = rev_sum1(n1, n2)
  
          expected = build_list([2])
          
          assert actual == expected
  
      def test_case5(self):
          
          n1, n2 = build_list([0, 0, 0, 0]), build_list([9, 9, 9, 9])
  
          actual = rev_sum1(n1, n2)
  
          expected = build_list([9, 9, 9, 9])
          
          assert actual == expected
  
      def test_case6(self):
          
          n1, n2 = build_list([6]), build_list([5, 9, 3])
  
          actual = rev_sum1(n1, n2)
  
          expected = build_list([4, 0, 1])
          
          assert actual == expected