def METHOD_NAME(self):
    # identifier should detect mirroring
    a = g.get_mesh('featuretype.STL')
    b = a.copy()
    b.vertices[:, 2] *= -1.0
    b.invert()
    assert g.np.isclose(a.volume, b.volume)
    # hash should differ
    assert a.identifier_hash != b.identifier_hash
    # a mesh which is quite sensitive to mirroring
    a = g.get_mesh('mirror.ply')
    b = a.copy()
    b.vertices[:, 2] *= -1.0
    b.invert()
    assert g.np.isclose(a.volume, b.volume)
    # hash should differ
    assert a.identifier_hash != b.identifier_hash