code: def testZeroSumSignal(self):
      signal = [1, -1, 1, -1, 1, -1, 0, 0, 0, 0]
      centroid = sum([i * fabs(x) for i, x in enumerate(signal)]) / sum(
          [fabs(x) for x in signal]
      )
      energy = sum([x * x for x in signal])
      self.assertAlmostEqual(
          StrongDecay(sampleRate=1)(signal),
          sqrt(float(energy) / float(centroid)),
      )
  
file_path: essentia/test/src/unittests/temporal/test_strongdecay.py
imports: from essentia_test import *
  from math import sqrt
  from math import fabs
label_desc: Use image node_id 7 for calling the TestStrongDecay obj's underlying member method code with example usage: obj.testZeroSumSignal() without return types