text: """This module contains tests of the utils module."""
  
  import os
  import numpy as np
  import numpy.testing as npt
  import matplotlib.pyplot as plt
  
  from .. import utils
  
  
  def test_vec2vec_rotmat():
      np.random.seed(123)
      for _ in range(100):
          a = np.random.random(3) - 0.5
          a_norm = np.linalg.norm(a)
          b = np.random.random(3) - 0.5
          b_norm = np.linalg.norm(b)
          R = utils.vec2vec_rotmat(a, b)
          npt.assert_array_almost_equal(np.linalg.norm(a), a_norm)
          npt.assert_array_almost_equal(np.linalg.norm(b), b_norm)
          a = np.matmul(R, a)
          a /= np.linalg.norm(a)
          b /= np.linalg.norm(b)
          npt.assert_array_almost_equal(a, b)
      return
  