output: #fixed code
                                  private Long getRequestStartTime() {
          final RequestContext ctx = RequestContext.getCurrentContext();
          final HttpServletRequest request = ctx.getRequest();
          return (Long) request.getAttribute(REQUEST_START_TIME);
      }
input: #vulnerable code 
                                  private Long getRequestStartTime() {
          RequestAttributes requestAttributes = RequestContextHolder.getRequestAttributes();
          return (Long) requestAttributes.getAttribute(REQUEST_START_TIME, SCOPE_REQUEST);
      } 
                              #location 3 
                              #vulnerability type NULL_DEREFERENCE