code: def _adjust_crop_box(box, crop):
          
  
          if crop and box:
              # Both boxes are the same size; just line them up.
              return (box[0] + crop[0], box[1] + crop[1],
                      box[2] + crop[0], box[3] + crop[1])
  
          if crop:
              # We don't have a fit box, so just convert the crop box
              return (crop[0], crop[1], crop[0] + crop[2], crop[1] + crop[3])
  
          # We don't have a crop box, so return the fit box (even if it's None)
          return box
docs: Given a fit box and a crop box, adjust one to the other