code: def template_save_to_file(
      self, visualizer_type, filename="ut-test-image.png"
  ):
      if (filename is not None) and (len(filename)) != 0:
          filename = tempfile.gettempdir() + os.sep + filename
  
      data = [
          [1.1],
          [1.7],
          [3.7],
          [5.3],
          [2.5],
          [-1.5],
          [-0.9],
          [6.3],
          [6.5],
          [8.1],
      ]
      clusters = [[0, 1, 2, 4, 5, 6], [3, 7, 8, 9]]
  
      visualizer = visualizer_type()
      visualizer.append_clusters(clusters, data)
      visualizer.save(filename)
  
      self.assertTrue(os.path.exists(filename))
      os.remove(filename)
  
imports: import unittest
  import os
  import tempfile
  import matplotlib
  from pyclustering.cluster import cluster_visualizer, cluster_visualizer_multidim
  from pyclustering.samples import answer_reader
  from pyclustering.samples.definitions import SIMPLE_SAMPLES, SIMPLE_ANSWERS, FAMOUS_SAMPLES, FAMOUS_ANSWERS
  from pyclustering.utils import read_sample
label_desc: Use image node_id 24 for calling the visualizer_unit_tests obj's underlying member method code with example usage: obj.template_save_to_file(visualizer_type, filename) without return types