code: def testConstantInput(self):
      beatPeriod = 21168  # N.B The beat period is 21168 samples for 125 bpm @ 44.1k samp. rate
      onesAudio = ones(beatPeriod)
      estimate = PercivalBpmEstimator()(onesAudio)
      # The observed BPM is also  104.4 for constant input of ones.
      self.assertAlmostEqual(estimate, 104.40341, 8)
  
      constantInput = [0.5 for i in range(21168)]
      estimate = PercivalBpmEstimator()(constantInput)
      # The observed BPM is also around 104.4 for another constant input value, 0.5
      self.assertAlmostEqual(estimate, 104.40341, 8)
  
      constantInput = [0.5 for i in range(21168)]
      # Repeat test but, tweak a config. parameters out of its default value.
      estimate = PercivalBpmEstimator(maxBPM=60)(constantInput)
      self.assertAlmostEqual(estimate, 104.40341, 8)
  
file_path: essentia/test/src/unittests/rhythm/test_percivalbpmestimator.py
imports: from essentia_test import *
  from essentia.standard import MonoLoader, PercivalBpmEstimator
label_desc: Use image node_id 7 for calling the TestPercivalBpmEstimator obj's underlying member method code with example usage: obj.testConstantInput() without return types