code: def test_cart_distance():
      a = [0, 1]
      b = [1, 0]
      assert_array_almost_equal(cart_distance(a, b), np.sqrt(2))
      assert_array_almost_equal(cart_distance([1, 0], [-1, 0]), 2)
      pts1 = [2, 1, 0]
      pts2 = [0, 1, -2]
      assert_array_almost_equal(cart_distance(pts1, pts2), np.sqrt(8))
      pts2 = [[0, 1, -2], [-2, 1, 0]]
      assert_array_almost_equal(
          cart_distance(pts1, pts2), [np.sqrt(8), 4]
      )
  
imports: import numpy
  import random
  from dipy.core.geometry import sphere2cart, cart2sphere, nearest_pos_semi_def, sphere_distance, cart_distance, vector_cosine, lambert_equal_area_projection_polar, circumradius, vec2vec_rotmat, vector_norm, compose_transformations, compose_matrix, decompose_matrix, perpendicular_directions, dist_to_corner, is_hemispherical
  from numpy.testing import assert_array_equal, assert_array_almost_equal, assert_equal, assert_raises, assert_almost_equal
  from dipy.testing.spherepoints import sphere_points
  from dipy.testing.decorators import set_random_number_generator
  from dipy.core.sphere_stats import random_uniform_on_sphere
  from itertools import permutations
label_desc: Use image node_id 5 for calling a global function with example usage: test_cart_distance() without return types