code: def setup_module():
      """Module-level setup"""
      global gtab, gtab_2s
  
      _, fbvals, fbvecs = get_fnames("small_64D")
      bvals, bvecs = read_bvals_bvecs(fbvals, fbvecs)
      gtab = gradient_table(bvals, bvecs)
  
      # 2 shells for techniques that requires multishell data
      bvals_2s = np.concatenate((bvals, bvals * 2), axis=0)
      bvecs_2s = np.concatenate((bvecs, bvecs), axis=0)
      gtab_2s = gradient_table(bvals_2s, bvecs_2s)
  
file_path: dipy/dipy/sims/tests/test_voxel.py
imports: import numpy
  from numpy.testing import assert_array_equal, assert_array_almost_equal, assert_, assert_almost_equal
  from dipy.sims.voxel import _check_directions, all_tensor_evecs, add_noise, single_tensor, sticks_and_ball, multi_tensor_dki, kurtosis_element, dki_signal, multi_tensor
  from dipy.data import get_fnames
  from dipy.core.gradients import gradient_table
  from dipy.io.gradients import read_bvals_bvecs
  from dipy.testing.decorators import set_random_number_generator
label_desc: Use image node_id 1 for calling a global function with example usage: setup_module() without return types