Library object has no attribute 'assignment_tag'

[djangojeng-e]

Hi,
I have tested the package with Django 3.1.2 and Django 2.1.1.
Each time I tried, I get to see the error that library object has no attribute 'assignment_tag'.

It was mentioned that this error raises if the package is used with Django below 1.9 but it seems like it is not the case as the same error occurs with Django 2+ and 3+.

Handling this error involved modifying carton_tags.py as below but this is not permanent solution for the package. (comment out assignment_tag and register simple_tag as below)

Would there be any other way to use this package without having to see this assignment_tag error?

`
def get_cart(context, session_key=None, cart_class=Cart):
"""
Make the cart object available in template.

Sample usage::

    {% load carton_tags %}
    {% get_cart as cart %}
    {% for product in cart.products %}
        {{ product }}
    {% endfor %}

request = context['request']
return cart_class(request.session, session_key=session_key)

register.assignment_tag(takes_context=True, name=CART_TEMPLATE_TAG_NAME)(get_cart)

register.simple_tag(takes_context=True, name=CART_TEMPLATE_TAG_NAME)(get_cart)
def get_cart(context, session_key=None, cart_class=Cart):
request = context['request']
return cart_class(request.session, session_key=session_key)`