#vulnerable code 
                             @RequestMapping("/error")
	@ResponseStatus(HttpStatus.OK)
	public Result<String> error() {
		RequestContext ctx = RequestContext.getCurrentContext();
		Throwable throwable = ctx.getThrowable();
		if(null != throwable && throwable instanceof  ZuulException ){
			ZuulException e = (ZuulException) ctx.getThrowable();
			return Result.error(e.nStatusCode, e.errorCause);
		}
		return Result.error(99,throwable.getMessage());
	} 
                            #location 10 
                            #vulnerability type NULL_DEREFERENCE
#fixed code
                             @RequestMapping("/error")
	@ResponseStatus(HttpStatus.OK)
	public Result<String> error() {
		RequestContext ctx = RequestContext.getCurrentContext();
		Throwable throwable = ctx.getThrowable();
		if(null != throwable && throwable instanceof  ZuulException ){
			ZuulException e = (ZuulException) ctx.getThrowable();
			return Result.error(e.nStatusCode, e.errorCause);
		}
		return Result.error(ResultEnum.ERROR);
	}