private static void verifyThemeFile(final String themeName) {
        val themeResolver = new FixedThemeResolver();
        themeResolver.setDefaultThemeName(themeName);
        val resolver = new ThemeClassLoaderTemplateResolver(themeResolver);
        resolver.setSuffix(".html");
        resolver.setCheckExistence(true);
        resolver.setPrefix("templates/%s/");
        val view = resolver.resolveTemplate(mock(IEngineConfiguration.class), StringUtils.EMPTY, "casLoginView", Map.of());
        assertNotNull(view);
    }
This is {@link ThemeClassLoaderTemplateResolverTests}.

@author Misagh Moayyed
@since 6.2.0
support/cas-server-support-thymeleaf/src/test/java/org/apereo/cas/web/view/ThemeClassLoaderTemplateResolverTests.java