code: def testVisualize2DClustersOneCanvasNumpy(self):
      sample = read_sample(
          SIMPLE_SAMPLES.SAMPLE_SIMPLE4, return_type="numpy"
      )
      clusters = dbscan(sample, 0.7, 3, False).process().get_clusters()
  
      visualizer = cluster_visualizer()
      visualizer.append_clusters(clusters, sample, markersize=5)
      figure = visualizer.show()
      visualizer.close(figure)
  
imports: import unittest
  import matplotlib
  import matplotlib.pyplot
  import numpy
  import random
  from pyclustering.samples.definitions import SIMPLE_SAMPLES, FCPS_SAMPLES
  from pyclustering.utils import read_sample
  from pyclustering.cluster import cluster_visualizer
  from pyclustering.cluster.dbscan import dbscan
  from pyclustering.cluster.cure import cure
label_desc: Use image node_id 10 for calling the Test obj's underlying member method code with example usage: obj.testVisualize2DClustersOneCanvasNumpy() without return types