code: def testOutputNormalization(self):
      network = sync_network(20, 1, ccore=False)
  
      output_dynamic = network.simulate(50, 20, solve_type.RK4)
  
      t = output_dynamic.time
      dyn = output_dynamic.output
  
      for iteration in range(len(dyn)):
          for index_oscillator in range(len(dyn[iteration])):
              assert dyn[iteration][index_oscillator] >= 0
              assert dyn[iteration][index_oscillator] <= 2.0 * pi
  
imports: import unittest
  import matplotlib
  from pyclustering.nnet.tests.sync_templates import SyncTestTemplates
  from pyclustering.nnet import solve_type, conn_type
  from pyclustering.nnet.sync import sync_network, sync_dynamic, sync_visualizer
  from pyclustering.utils import pi
label_desc: Use image node_id 6 for calling the SyncUnitTest obj's underlying member method code with example usage: obj.testOutputNormalization() without return types