def test_get_angles():
    from ase.build import graphene_nanoribbon
    import numpy as np

    g = graphene_nanoribbon(3, 2, type="zigzag", vacuum=5)

    test_set = [[0, 1, x] for x in range(2, len(g))]

    manual_results = [g.get_angle(a1, a2, a3, mic=True) 
                      for a1, a2, a3 in test_set]

    set_results = g.get_angles(test_set, mic=True)

    assert(np.allclose(manual_results, set_results))