title: Proper way to document that a class implements a collections interface?
body: <p>Assuming I have a class that implements the Sequence interface, i.e. has <code>__len__</code> and <code>__getitem__</code> methods, what is the recommended way to document this? Is an informal description in the classes docstring enough, should I subclass <code>collections.abc.Sequence</code> or do something else entirely?</p>