code: def testZero(self):
      filt = self.loadSimpleFilter()
      self.assertEqualVector(filt(zeros(20)), zeros(20))
  
file_path: essentia/test/src/unittests/filters/test_iir.py
imports: from essentia_test import *
label_desc: Use image node_id 5 for calling the TestIIR obj's underlying member method code with example usage: obj.testZero() without return types