protected List<Matcher> retrieveMatchers(final String matcherName, final Map<String, Matcher> matchersMap) {
        final List<Matcher> results = new ArrayList<>();
        for (val entry : matchersMap.entrySet()) {
            if (areEqualsIgnoreCaseAndTrim(entry.getKey(), matcherName)) {
                results.add(entry.getValue());
                break;
            }
        }
        if (results.size() == 0) {
            if (DefaultMatchers.HSTS.equalsIgnoreCase(matcherName)) {
                return List.of(STRICT_TRANSPORT_MATCHER);
            } else if (DefaultMatchers.NOSNIFF.equalsIgnoreCase(matcherName)) {
                return List.of(X_CONTENT_TYPE_OPTIONS_MATCHER);
            } else if (DefaultMatchers.NOFRAME.equalsIgnoreCase(matcherName)) {
                return List.of(X_FRAME_OPTIONS_MATCHER);
            } else if (DefaultMatchers.XSSPROTECTION.equalsIgnoreCase(matcherName)) {
                return List.of(XSS_PROTECTION_MATCHER);
            } else if (DefaultMatchers.NOCACHE.equalsIgnoreCase(matcherName)) {
                return List.of(CACHE_CONTROL_MATCHER);
            } else if (DefaultMatchers.CSRF_TOKEN.equalsIgnoreCase(matcherName)) {
                return List.of(CSRF_TOKEN_MATCHER);
            } else if (DefaultMatchers.ALLOW_AJAX_REQUESTS.equalsIgnoreCase(matcherName)) {
                return List.of(CORS_MATCHER);
            } else if (DefaultMatchers.GET.equalsIgnoreCase(matcherName)) {
                return List.of(GET_MATCHER);
            } else if (DefaultMatchers.POST.equalsIgnoreCase(matcherName)) {
                return List.of(POST_MATCHER);
            } else if (DefaultMatchers.PUT.equalsIgnoreCase(matcherName)) {
                return List.of(PUT_MATCHER);
            } else if (DefaultMatchers.DELETE.equalsIgnoreCase(matcherName)) {
                return List.of(DELETE_MATCHER);
            }
        }
        return results;
    }
<p>retrieveMatchers.</p>

@param matcherName a {@link String} object
@param matchersMap a {@link Map} object
@return a {@link List} object
pac4j-core/src/main/java/org/pac4j/core/matching/checker/DefaultMatchingChecker.java