code: def split_box( fraction, x,y, w,h ):
      
      if w >= h:
          new_w = int(w*fraction)
          if new_w:
              return (x,y,new_w,h),(x+new_w,y,w-new_w,h)
          else:
              return None,None
      else:
          new_h = int(h*fraction)
          if new_h:
              return (x,y,w,new_h),(x,y+new_h,w,h-new_h)
          else:
              return None,None
docs: Return set of two boxes where first is the fraction given