Retrieve a single resource.

        This should only be called from sub-classes.

        Args:

            session(Session): The session to find the resource in

            resource_id: The ``id`` for the resource to look up

        Keyword Args:

            include: Resource classes to include

        Returns:

            Resource: An instance of a resource, or throws a
              :class:`NotFoundError` if the resource can not be found.

def find(cls, session, resource_id, include=None):
        """Retrieve a single resource.

        This should only be called from sub-classes.

        Args:

            session(Session): The session to find the resource in

            resource_id: The ``id`` for the resource to look up

        Keyword Args:

            include: Resource classes to include

        Returns:

            Resource: An instance of a resource, or throws a
              :class:`NotFoundError` if the resource can not be found.

        """
        url = session._build_url(cls._resource_path(), resource_id)
        params = build_request_include(include, None)
        process = cls._mk_one(session, include=include)
        return session.get(url, CB.json(200, process), params=params)