code: def _get_invalid_style_cases(self):
      style_cases = []
      # when style is an empty list
      style_cases.append([])
      # when style is a list, but index is not within the number of styles
      style_cases.append([self.num_styles + 10])
      # when style is a int, but index is not within the number of styles
      style_cases.append(self.num_styles + 10)
      # when style is a str, and is empty
      style_cases.append("")
      # when style is a str, and is not within label names
      style_cases.append("style_image_404")
  
      return style_cases
  
imports: from __future__ import print_function
  from __future__ import division
  from __future__ import absolute_import
  import unittest
  import pytest
  from .None import util
  import turicreate
  import tempfile
  import numpy
  import platform
  import sys
  import os
  from turicreate.toolkits._main import ToolkitError
  from turicreate.toolkits._internal_utils import _raise_error_if_not_sframe, _mac_ver
label_desc: Use image node_id 13 for calling the StyleTransferTest obj's underlying member method code with example usage: obj._get_invalid_style_cases() and returns: style_cases