code: def test_sticks_and_ball():
      d = 0.0015
      S, sticks = sticks_and_ball(
          gtab,
          d=d,
          S0=1,
          angles=[
              (0, 0),
          ],
          fractions=[100],
          snr=None,
      )
      assert_array_equal(sticks, [[0, 0, 1]])
      S_st = single_tensor(
          gtab,
          1,
          evals=[d, 0, 0],
          evecs=[[0, 0, 0], [0, 0, 0], [1, 0, 0]],
      )
      assert_array_almost_equal(S, S_st)
  
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 3 for calling a global function with example usage: test_sticks_and_ball() without return types