Create the namespace from the view
    :param view: object (class or instance method)
    :param cls_name: str - To pass the class name associated to the view
            in the case of decorators that may not give the real class name
    :return: string or None

def view_namespace(view, cls_name=None):
    """
    Create the namespace from the view
    :param view: object (class or instance method)
    :param cls_name: str - To pass the class name associated to the view
            in the case of decorators that may not give the real class name
    :return: string or None
    """
    ns = view.__module__
    if inspect.isclass(view):
        ns += ".%s" % view.__name__
    else:
        if hasattr(view, "im_class") or hasattr(view, "im_self"):
            if view.im_class is not None:
                cls_name = view.im_class.__name__
            elif view.im_self is not None:
                cls_name = view.im_self.__name__
        if cls_name is None:
            return None
        ns += ".%s.%s" % (cls_name, view.__name__)
    return ns