old_contents: """Convert boolean value to yes or no."""
  
  
  def bool_to_yes_no(value):
      """Convert value if boolean to yes or no.
  
      Args:
          boolean: Value to check.
  
      Returns:
          "yes" if boolean is True, "no" if False.
  
      Raises:
          ValueError if value isn't "yes" or "no".
      """
      if type(value) == bool and value:
          return "yes"
      elif type(value) == bool:
          return "no"
      else:
          raise ValueError("Expected 'yes' or 'no'.")
  
new_contents: """Convert boolean value to yes or no."""
  
  
  def bool_to_yes_no(value):
      """Convert value if boolean to yes or no.
  
      Args:
          boolean: Value to check.
  
      Returns:
          "yes" if boolean is True, "no" if False.
  
      Raises:
          ValueError if value isn't "yes" or "no".
      """
      if type(value) == bool and value:
          return "yes"
      elif type(value) == bool:
          return "no"
      else:
          raise ValueError("Expected True or False.")
  
subject: Fix docstring