def test_read_write_unknown():
    ctx = Context()

    needle = 'xyzzy'
    assert needle not in _default_context.keys()
    assert needle not in ctx
    assert_raises(KeyError, lambda: ctx[needle])
    assert_raises(KeyError, ctx.__setitem__, needle, Nothing)
dataset/ETHPy150Open jek/flatland/tests/markup/test_context.py/test_read_write_unknown/original