[Help] How to check if cart needs shipping

[igoraugustynski]

Hello,
I'm currently building a custom checkout flow using swell-js and Angular. I managed to implement pretty much all of the needed functionality but I'm struggling with one issue:
How do I know, using swell-js, if a cart needs shipping? i.e. it does have physical items, not only digital ones?
cart.getShippingRates() seems to return shipment services even if the cart contains only digital items, and I do not see any useful property on the cart object.