code: def testSingle(self):
      self.assertAlmostEqual(Flux()([100]), 100)
  
file_path: essentia/test/src/unittests/spectral/test_flux.py
imports: from essentia_test import *
label_desc: Use image node_id 3 for calling the TestFlux obj's underlying member method code with example usage: obj.testSingle() without return types