code: def testBelowReferenceFrequency2(self):
      freq_speaks = [30]
      mag_speaks = [1]
      outputLength = 600
      expectedPitchSalience = zeros(outputLength)
      calculatedPitchSalience = PitchSalienceFunction(
          referenceFrequency=40
      )(freq_speaks, mag_speaks)
      self.assertEqualVector(
          calculatedPitchSalience, expectedPitchSalience
      )
  
imports: from essentia_test import *
  from numpy import *
label_desc: Use image node_id 14 for calling the TestPitchSalienceFunction obj's underlying member method code with example usage: obj.testBelowReferenceFrequency2() without return types