old_contents: import pytest
  
  from nlppln.generate import to_bool
  
  
  def test_to_bool_correct():
      assert to_bool('y') == True
      assert to_bool('n') == False
  
  
  def test_to_bool_error():
      with pytest.raises(ValueError):
          to_bool('foo')
  
new_contents: import pytest
  
  from nlppln.generate import to_bool
  
  
  def test_to_bool_correct():
      assert to_bool('y') is True
      assert to_bool('n') is False
  
  
  def test_to_bool_error():
      with pytest.raises(ValueError):
          to_bool('foo')
  
subject: Fix code style