new_contents: import unittest
  from maximumSubarray import Solution
  
  class TestMaximumSubarrayEdgeCases(unittest.TestCase):
      def setUp(self):
          self.solution = Solution()
  
      def testEmptyArrayReturnsZero(self):
          self.assertRaises(ValueError, self.solution.maxSubArray, [])
  
      def testArrayWithSingleEntryReturnsEntry(self):
          self.assertEqual(self.solution.maxSubArray([-1,]), -1)
          self.assertEqual(self.solution.maxSubArray([0,]), 0)
          self.assertEqual(self.solution.maxSubArray([1,]), 1)
  
  class TestMaximumSubarrayWithExamples(unittest.TestCase):
      def setUp(self):
          self.solution = Solution()
  
      def testArrayWithAllNegativeNumbersReturnsLeastNegative(self):
          testArray = [-6, -5, -2, -4, -3]
          self.assertEqual(self.solution.maxSubArray(testArray), -2)
  
      def testArrayWithNegativeNumbersAndZeroReturnsZero(self):
          testArray = [-6, -5, 0, -4, -3, -2]
          self.assertEqual(self.solution.maxSubArray(testArray), 0)
  
      def testProblemExampleReturns6(self):
          testArray = [-2, 1, -3, 4, -1, 2, 1, -5, 4]
          self.assertEqual(self.solution.maxSubArray(testArray), 6)
  
  if __name__ == '__main__':
      unittest.main()
  
subject: Add 5 test cases for maximumSubarray problem.