def test_get_offset_0_bit():
    """get_offset should return None if no bits are allocated to an offset"""
    nose.assert_is_none(
        sim.get_offset('10110100', num_offset_bits=0))
def test_get_offset_2_bit():
    """get_offset should return correct 2 offset bits for an address"""
    nose.assert_equal(
        sim.get_offset('11111101', num_offset_bits=2),
        '01')