code: def test_next_fast_len():
      for size in range(1, 1000):
          assert next_fast_len(size) == fftpack.next_fast_len(size)
  
imports: import math
  import numpy
  import pytest
  import scipy.fftpack
  import torch
  import pyro
  from pyro.ops.tensor_utils import block_diag_embed, block_diagonal, convolve, dct, idct, next_fast_len, periodic_cumsum, periodic_features, periodic_repeat, precision_to_scale_tril, repeated_matmul
  from tests.common import assert_close, assert_equal
label_desc: Use image node_id 12 for calling a global function with example usage: test_next_fast_len() without return types