def test_is_IFrame1():
"""test non-I-frame for being one."""
iframe = IFrame()
iframe.set_control(bytes([128]))
assert iframe.is_IFrame() is False
def test_is_IFrame0():
"""set I-frame bit and control for it."""
iframe = IFrame()
iframe.set_control(bytes([42]))
assert iframe.is_IFrame() is True
