code: def testDownSampling(self):
      # files of 30s with impulses at every sample
      # from 44100 to 22050
      filename = join(resamp_dir, "impulses_1samp_44100.wav")
      left = self.load(filename, "left", 22050)
      self.assertAlmostEqual(sum(left), 30.0 * 22050, 1e-4)
      # from 48000 to 44100
      filename = join(resamp_dir, "impulses_1samp_48000.wav")
      left = self.load(filename, "left", 44100)
      self.assertAlmostEqual(sum(left), 30.0 * 44100, 1e-4)
      # from 48000 to 22050
      left = self.load(filename, "left", 22050)
      self.assertAlmostEqual(sum(left), 30.0 * 22050, 1e-4)
  
imports: from essentia_test import *
  from numpy import fabs
label_desc: Use image node_id 17 for calling the TestMonoLoader obj's underlying member method code with example usage: obj.testDownSampling() without return types