code: def testZero(self):
      zeroInput = [0] * 10
      self.assertEquals(PowerMean()(zeroInput), 0)
  
file_path: essentia/test/src/unittests/stats/test_powermean.py
imports: from essentia_test import *
label_desc: Use image node_id 2 for calling the TestPowerMean obj's underlying member method code with example usage: obj.testZero() without return types