code: def testOne(self):
      oneInput = [100]
      self.assertAlmostEqual(PowerMean()(oneInput), oneInput[0])
      self.assertAlmostEqual(PowerMean(power=0)(oneInput), oneInput[0])
      self.assertAlmostEqual(PowerMean(power=-2)(oneInput), oneInput[0])
      self.assertAlmostEqual(
          PowerMean(power=6)(oneInput), oneInput[0], 1e-6
      )
  
file_path: essentia/test/src/unittests/stats/test_powermean.py
imports: from essentia_test import *
label_desc: Use image node_id 3 for calling the TestPowerMean obj's underlying member method code with example usage: obj.testOne() without return types