docstr: Test that the coordinate projection functions are in fact inverses.
code: def test_coordinate_maps():
      """Test that the coordinate projection functions are in fact inverses."""
  
      def random_point(scale=1):
          x = random.random() * scale
          y = random.random() * (scale - x)
          z = scale - x - y
          return x, y, z
  
      for _ in range(20):
          scale = random.randint(1, 100)
          p = random_point(scale=scale)
          projected = project_point(p)
          p2 = planar_to_coordinates(projected, scale=scale)
          assert_array_almost_equal(p, p2)
  
file_path: python-ternary/tests/test_helpers.py
imports: import random
  import unittest
  from numpy.testing import assert_array_equal, assert_array_almost_equal
  from ternary.helpers import normalize, project_point, planar_to_coordinates, simplex_iterator, SQRT3OVER2
label_desc: Use image node_id 6 for calling the FunctionCases obj's underlying member method code with example usage: obj.test_coordinate_maps() and returns: x,  y,  z