line_quantities in Order Pipeline

[P. Maung Maung]

Hi, I'm new to django-oscar. So far, what I understand is when an order is created, there are lines for products. I can access lines via order object. What about line_quantities? I thought line_quantities is the number of lines. Actually it's iteratable. I was trying to override the processing.py in the order app. In short, can anyone please explain me what line_quantities and how to access it. I googled it first before I post here, still I cannot find it yet. Thank you.