#vulnerable code 
                             @Override
	public Object getParamValue(Req req, Class<?> paramType, String paramName, Map<String, Object> properties) throws Exception {
		return req.custom().jackson().convertValue(properties, paramType);
	} 
                            #location 3 
                            #vulnerability type NULL_DEREFERENCE
#fixed code
                             @Override
	public Object getParamValue(Req req, Class<?> paramType, String paramName, Map<String, Object> properties) throws Exception {
		return Customization.of(req).jackson().convertValue(properties, paramType);
	}