code: def testRegression(self):
      size = 2048
      test_signal = array(numpy.random.rand(2, size))
      test_signal = test_signal[0] + 1j * test_signal[1]
  
      # Use random values and compare with the Numpy Complex FFT.
      self.assertAlmostEqualVector(
          FFTC(negativeFrequencies=True)(test_signal),
          numpy.fft.fft(test_signal),
          1e-4,
      )
  
file_path: essentia/test/src/unittests/standard/test_fftc.py
imports: from essentia_test import *
  import math
label_desc: Use image node_id 5 for calling the TestFFT obj's underlying member method code with example usage: obj.testRegression() without return types