code: def test_all_tensor_evecs():
      e0 = np.array([1 / np.sqrt(2), 1 / np.sqrt(2), 0])
  
      # Vectors are returned column-wise!
      desired = np.array(
          [
              [1 / np.sqrt(2), 1 / np.sqrt(2), 0],
              [-1 / np.sqrt(2), 1 / np.sqrt(2), 0],
              [0, 0, 1],
          ]
      ).T
  
      assert_array_almost_equal(all_tensor_evecs(e0), desired)
  
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 7 for calling a global function with example usage: test_all_tensor_evecs() without return types