old_contents: from stack import Stack
  import pytest
  
  
  def test_stack_push():
      stack = Stack()
      stack.push("bacon")
      assert stack.top.value == "bacon"
      assert stack.peek() == "bacon"
  
  
  def test_stack_push_multi():
      stack = Stack()
      stack.push("bacon")
      stack.push("steak")
      stack.push("grilled cheese")
      stack.pop()
      stack.pop()
      assert stack.pop() == "bacon"
  
  
  def test_empty_stack_pop():
      stack = Stack()
      with pytest.raises(ValueError):
          stack.pop()
  
new_contents: from stack import Stack
  import pytest
  
  
  def test_stack_push():
      stack = Stack()
      stack.push("bacon")
      assert stack.top.value == "bacon"
      assert stack.peek() == "bacon"
  
  
  def test_stack_push_multi():
      stack = Stack()
      stack.push("bacon")
      stack.push("steak")
      stack.push("grilled cheese")
      assert stack.pop() == "grilled cheese"
      assert stack.pop() == "steak"
      assert stack.pop() == "bacon"
  
  
  def test_empty_stack_pop():
      stack = Stack()
      with pytest.raises(ValueError):
          stack.pop()
  
  
  def test_empty_stack_peek():
      stack = Stack()
      with pytest.raises(ValueError):
          stack.peek()
  
subject: Add test for peek on empty stack