code: def test_next_fast_len():
      for n in _5_smooth_numbers:
          assert_equal(next_fast_len(n), n)
  
imports: from scipy.fft._helper import next_fast_len, _init_nd_shape_and_axes
  from numpy.testing import assert_equal
  from pytest import raises
  import pytest
  import numpy
  import sys
  from scipy.conftest import array_api_compatible, skip_if_array_api_gpu, skip_if_array_api_backend
  from scipy._lib._array_api import xp_assert_close, SCIPY_DEVICE
  from scipy import fft
label_desc: Use image node_id 1 for calling a global function with example usage: test_next_fast_len() without return types