Exercise 1b) Implement the decay parameter as a property 1p Turn the decay parameter a into a property. Implement a setter method that throws a ValueError if the provided value is negative. Use this setter method in the constructor and write a test function test negative_decay_raises_ValueError that verifies that the following code raises a ValueError: model ExponentialDecay (0.4) model.decay = -1.0 Hint - writing properties with private variables You can read about properties with getters and setters in the lecture notes on properties or in the slides on classes in Python.