code: def _helper3(self, a):
      # this tests CUDA library calls
      a = a * cupy.fft.fft(a)
      return cupy.fft.ifft(a)
  
imports: import pytest
  import cupy
  from cupy import cuda
  from cupy import testing
  import cupyx
label_desc: Use image node_id 3 for calling the TestGraph obj's underlying member method code with example usage: obj._helper3(a) and returns: cupy