code: def test_triangles_area():
      cube_tri, cube_vts = create_cube()
      area = triangles_area(cube_tri, cube_vts)
      npt.assert_array_equal(area, 0.5)
      cube_vts *= 2.0
      area = triangles_area(cube_tri, cube_vts)
      npt.assert_array_equal(area, 2.0)
  
imports: import numpy
  import numpy.testing
  from dipy.tracking.mesh import triangles_area, random_coordinates_from_surface, seeds_from_surface_coordinates, vertices_to_triangles_values
label_desc: Use image node_id 2 for calling a global function with example usage: test_triangles_area() without return types