code: def testVisualizeUnusedCanvasesNoCrash(self):
      t = [0, 1, 2, 3, 4, 5, 6, 7]
      y = [0, 0, 1, 2, 0, 1, 2, 0]
  
      visualizer = dynamic_visualizer(3)
      visualizer.append_dynamic(t, y, canvas=0, color="red")
  
file_path: pyclustering/pyclustering/nnet/tests/unit/ut_dynamic_visualizer.py
imports: import unittest
  import matplotlib
  from pyclustering.nnet.dynamic_visualizer import dynamic_visualizer
label_desc: Use image node_id 8 for calling the DynamicVisualizerUnitTest obj's underlying member method code with example usage: obj.testVisualizeUnusedCanvasesNoCrash() without return types