code: def loadSimpleFilter(self):
      a = readVector(join(filedir(), "filters/a.txt"))
      b = readVector(join(filedir(), "filters/b.txt"))
      return IIR(numerator=b, denominator=a)
  
file_path: essentia/test/src/unittests/filters/test_iir.py
imports: from essentia_test import *
label_desc: Use image node_id 1 for calling the TestIIR obj's underlying member method code with example usage: obj.loadSimpleFilter() and returns: IIR