def METHOD_NAME(self, refUniverse):
    # check that coordinates act independently
    new = refUniverse.copy()
    previous = new.atoms[0].position.copy()
    refUniverse.atoms[0].position = 1, 2, 3
    assert_equal(new.atoms[0].position, previous)
    assert_equal(refUniverse.atoms[0].position, [1, 2, 3])