code: def testFFTConv(self):
      np.random.seed(10003)
      x = np.random.randn(100).astype(np.float32)
      y = np.random.randn(100).astype(np.float32)
      x_conv_y_np = np.convolve(x, y)
      x_conv_y_fft = vectorized_stochastic_volatility._fft_conv(x, y)
      self.assertAllClose(x_conv_y_np, x_conv_y_fft, rtol=1e-3)
  
imports: import functools
  from absl import logging
  from absl.testing import parameterized
  import numpy
  import tensorflow.compat.v2
  import tensorflow_probability
  from tensorflow_probability.python.internal import test_util
  from inference_gym.internal import test_util
  from inference_gym.targets import vectorized_stochastic_volatility
  from tensorflow.python.util import nest
label_desc: Use image node_id 4 for calling the VectorizedStochasticVolatilityTest obj's underlying member method code with example usage: obj.testFFTConv() without return types