@Override
    public NacosUser authenticate(String username, String rawPassword) throws AccessException {
        if (StringUtils.isBlank(username) || StringUtils.isBlank(rawPassword)) {
            throw new AccessException("user not found!");
        }
        NacosUserDetails nacosUserDetails = (NacosUserDetails) userDetailsService.loadUserByUsername(username);
        if (nacosUserDetails == null || !PasswordEncoderUtil.matches(rawPassword, nacosUserDetails.getPassword())) {
            throw new AccessException("user not found!");
        }
        return new NacosUser(nacosUserDetails.getUsername(), jwtTokenManager.createToken(username));
    }
@Test
    void testAuthenticate4() {
        when(userDetailsService.loadUserByUsername(anyString())).thenReturn(null);
        
        assertThrows(AccessException.class, () -> {
            abstractAuthenticationManager.authenticate("nacos", "test");
        });
    }