message: Add a test that fixes
diff: from gudhi import AlphaComplex, SimplexTree
  +import math
  +import numpy as np
  +import itertools
  +import pytest
  """ This file is part of the Gudhi Library - https://gudhi.inria.fr/ - which is released under MIT.
  See file LICENSE or go to https://gudhi.inria.fr/licensing/ for full license details.
  @@ -88,3 +92,34 @@ def test_filtered_alpha():
  ]
  assert simplex_tree.get_star([0]) == [([0], 0.0), ([0, 1], 0.25), ([0, 2], 0.25)]
  assert simplex_tree.get_cofaces([0], 1) == [([0, 1], 0.25), ([0, 2], 0.25)]
  +
  +def alpha_persistence_comparison(exact_version):
  + #generate periodic signal
  + time = np.arange(0, 10, 1)
  + signal = [math.sin(x) for x in time]
  + delta = math.pi
  + delayed = [math.sin(x + delta) for x in time]
  +
  + #construct embedding
  + embedding1 = [[signal[i], -signal[i]] for i in range(len(time))]
  + embedding2 = [[signal[i], delayed[i]] for i in range(len(time))]
  +
  + #build alpha complex and simplex tree
  + alpha_complex1 = AlphaComplex(points=embedding1)
  + simplex_tree1 = alpha_complex1.create_simplex_tree(exact_version = exact_version)
  +
  + alpha_complex2 = AlphaComplex(points=embedding2)
  + simplex_tree2 = alpha_complex2.create_simplex_tree(exact_version = exact_version)
  +
  + diag1 = simplex_tree1.persistence()
  + diag2 = simplex_tree2.persistence()
  +
  + for (first_p, second_p) in itertools.zip_longest(diag1, diag2):
  + assert first_p[0] == pytest.approx(second_p[0])
  + assert first_p[1] == pytest.approx(second_p[1])
  +
  +def test_exact_alpha_version():
  + alpha_persistence_comparison(exact_version = True)
  +
  +def test_safe_alpha_version():
  + alpha_persistence_comparison(exact_version = False)
  