extracting(sku, quantity) with one wrong quantity:
  Expecting actual:
    [("BOOK-1", 2), ("PEN-7", 10), ("BAG-3", 1)]
  to contain exactly (and in same order):
    [("BOOK-1", 2), ("PEN-7", 11), ("BAG-3", 1)]
  but some elements were not found:
    [("PEN-7", 11)]
  and others were not expected:
    [("PEN-7", 10)]