code: public void cart_cartId_coupon_DELETE(String cartId, String coupon) throws IOException {
  		String qPath = "/order/cart/{cartId}/coupon";
  		StringBuilder sb = path(qPath, cartId);
  		query(sb, "coupon", coupon);
  		execN(qPath, "DELETE", sb.toString(), null);
  	}
docs: Delete a coupon from cart
  
  REST: DELETE /order/cart/{cartId}/coupon
  @param cartId [required] Cart identifier
  @param coupon [required] Coupon identifier