mock-property

For simple use by people unfamiliar with descriptors, but wanting to safely put back the old state after overwriting a property, a simple save and restore might be useful. Two cases where I have wanted to do this are setting an environment variable for a unit test, and hacking to run a unit test. I suspect this is equivalent to is a delete in the first operation to clear the way for whatever I do, and perhaps doesn't make sense as a "mock" pattern. Could be wishful thinking that this might be a possible helper routine. 😄 Edit: a better description of the usage pattern might be "stash" and "restore". e.g.