    public void preflightCheckNegative() {
        String origin = "http://bla.com";
        String headers ="X-Data: Test";
        expect(backend.isOriginAllowed(origin,false)).andReturn(false);
        replay(backend);

        Map<String,String> ret =  handler.handleCorsPreflightRequest(origin, headers);
        assertNull(ret.get("Access-Control-Allow-Origin"));
    }
The web application does not, or can not, sufficiently verify whether a well-formed, valid, consistent request was intentionally provided by the user who submitted the request.