code: def test_value(self):
      image = (
          torch.arange(16).reshape(1, 4, 4).repeat(3, 1, 1).long() * 16
      )
      out = image_to_string(image)
  
      expected = (
          "\033[48;5;16m  \033[48;5;16m  \033[48;5;16m  \033[48;5;59m  \033[0m\n"
          "\033[48;5;59m  \033[48;5;59m  \033[48;5;59m  \033[48;5;59m  \033[0m\n"
          "\033[48;5;102m  \033[48;5;102m  \033[48;5;145m  \033[48;5;145m  \033[0m\n"
          "\033[48;5;145m  \033[48;5;188m  \033[48;5;188m  \033[48;5;231m  \033[0m\n"
      )
      assert out == expected
  
imports: import pytest
  import torch
  from kornia.utils import image_to_string, print_image
label_desc: Use image node_id 1 for calling the TestImageToString obj's underlying member method code with example usage: obj.test_value() without return types