code: def testClusterAllocationSampleSimple8(self):
      self.templateClusterAllocation(
          SIMPLE_SAMPLES.SAMPLE_SIMPLE8, [15, 30, 20, 80], 4
      )
  
imports: import unittest
  import matplotlib
  from pyclustering.samples.definitions import SIMPLE_SAMPLES, FCPS_SAMPLES
  from pyclustering.utils import read_sample
  from pyclustering.container.cftree import measurement_type
  from pyclustering.cluster.encoder import type_encoding
  from pyclustering.cluster.birch import birch
  from random import random
label_desc: Use image node_id 20 for calling the BirchUnitTest obj's underlying member method code with example usage: obj.testClusterAllocationSampleSimple8() without return types