old_contents: import unittest
  
  from app.calculator import Calculator
  
  
  class TestCalculator(unittest.TestCase):
  
      def setUp(self):
          self.calc = Calculator()
  
      def test_calculator_addition_method_returns_correct_result(self):
          calc = Calculator()
          result = calc.addition(2,2)
          self.assertEqual(4, result)
  
      def test_calculator_subtraction_method_returns_correct_result(self):
          calc = Calculator()
          result = calc.substraction(4,2)
          self.assertEqual(2, result)
  
new_contents: import unittest
  
  from app.calculator import Calculator
  
  
  class TestCalculator(unittest.TestCase):
  
      def setUp(self):
          self.calc = Calculator()
  
      def test_calculator_addition_method_returns_correct_result(self):
          calc = Calculator()
          result = calc.addition(2,2)
          self.assertEqual(4, result)
  
      def test_calculator_subtraction_method_returns_correct_result(self):
          calc = Calculator()
          result = calc.substraction(4,2)
          self.assertEqual(2, result)
  
      def test_calculator_division_method_returns_correct_result(self):
          calc = Calculator()
          result = calc.division(5,2)
          self.assertEqual(2.5, result)
  
subject: Add new test for division