@Override
    public JsonWebKeySet load(final OidcJsonWebKeyCacheKey cacheKey) {
        val jwks = buildJsonWebKeySet(cacheKey);
        if (jwks.isEmpty()) {
            LOGGER.warn("JSON web keystore retrieved is empty for issuer [{}]", cacheKey.getIssuer());
            return null;
        }
        val keySet = jwks.get();
        if (keySet.getJsonWebKeys().isEmpty()) {
            LOGGER.warn("JSON web keystore retrieved [{}] contains no JSON web keys", keySet);
            return null;
        }
        val keys = getJsonWebKeysFromJwks(keySet, cacheKey);
        LOGGER.debug("Found JSON web key as [{}]", keys);
        return keys.getJsonWebKeys().isEmpty() ? null : keys;
    }
Gets json web key from jwks.

@param jwks     the jwks
@param cacheKey the cache key
@return the json signing web key from jwks
support/cas-server-support-oidc-core-api/src/main/java/org/apereo/cas/oidc/jwks/OidcDefaultJsonWebKeystoreCacheLoader.java