old_contents: import pytest
  from monetPy.box import Box
  
  
  def test():
      box = Box(42)
      assert box.map(lambda value: value + 1) == Box(43)
  
new_contents: import pytest
  from monetPy.box import Box
  
  
  def test_eq_should_compare_only_box_value():
      assert Box(42) == Box(42)
      assert Box(43) != Box(42)
      assert Box([]) == Box([])
      assert Box({}) == Box({})
      assert Box(None) == Box(None)
  
  
  def test_map_should_return_box_with_mapped_value():
      box = Box(42)
      assert box.map(lambda value: value + 1) == Box(43)
  
  
  def test_map_should_return_new_instance_of_box():
      box = Box(42)
      mapped_box = box.map(lambda value: value + 1)
      assert box is not mapped_box
  
  
  def test_fold_should_return_result_of_fold_function_called_with_box_value():
      box = Box(42)
      assert box.fold(lambda value: value + 1) == 43
  
subject: add some unit test for box