protected BaseOAuth20IntrospectionAccessTokenResponse internalVerifyOperation(final String auth,
                                                                                  final OAuthRegisteredService registeredService) throws Throwable {
        val request = new MockHttpServletRequest();
        val response = new MockHttpServletResponse();

        val value = EncodingUtils.encodeBase64(auth.getBytes(StandardCharsets.UTF_8));
        request.addHeader(HttpConstants.AUTHORIZATION_HEADER, HttpConstants.BASIC_HEADER_PREFIX + value);

        val mv = generateAccessTokenResponseAndGetModelAndView(registeredService);
        val at = mv.getModel().get(OAuth20Constants.ACCESS_TOKEN).toString();

        request.addParameter(OAuth20Constants.TOKEN, at);
        val entity = introspectionEndpoint.handleRequest(request, response);
        return entity.getBody();
    }
This is {@link OAuth20IntrospectionEndpointControllerTests}.

@author Misagh Moayyed
@since 6.1.0
support/cas-server-support-oauth/src/test/java/org/apereo/cas/support/oauth/web/endpoints/OAuth20IntrospectionEndpointControllerTests.java