What's the difference between Variable and ResourceVariable in Tensorflow : <p>In tensorflow, Variable is a resource, inherited from ResourceBase and managed by ResourceMgr. But why there is another thing named ResourceVariable? Both of them can be used for optimizers like gradient_descent(see this <a href="https://github.com/tensorflow/tensorflow/blob/master/tensorflow/python/training/gradient_descent_test.py" rel="noreferrer">example</a>). What's the difference? I know the former one is well documented and most often used. What's the purpose of the later one?</p>
