manage callback with unrestraint

tests/test_option_callback.py

@@ -1298,6 +1298,21 @@ async def test_callback_calculating_invalid():
     assert not await list_sessions()
 
 
+@pytest.mark.asyncio
+async def test_callback_unrestraint():
+    opt1 = IntOption('opt1', '', 1)
+    opt2 = IntOption('opt2', '', Calculation(return_value, Params(ParamOption(opt1))))
+    od1 = OptionDescription('od1', '', [opt1], properties=('disabled',))
+    od2 = OptionDescription('od2', '', [opt2])
+    maconfig = OptionDescription('rootconfig', '', [od1, od2])
+    async with await Config(maconfig) as cfg:
+        await cfg.property.read_write()
+        with pytest.raises(ConfigError):
+            await cfg.option('od2.opt2').value.get()
+        assert await cfg.unrestraint.option('od2.opt2').value.get() == 1
+    assert not await list_sessions()
+
+
 @pytest.mark.asyncio
 async def test_callback_calculating_disabled():
     opt1 = BoolOption('opt1', '', properties=('disabled',))