@Override
            protected boolean removeEldestEntry(Map.Entry<String, Long> eldest) {
                return this.size() > MISSING_KEY_ID_CACHE_MAX_ENTRIES;
            }
Creates a <code>RefreshingHttpsJwks</code>. It should only be used for testing to pass in a mock executor
service. Otherwise the constructor below should be used.
clients/src/main/java/org/apache/kafka/common/security/oauthbearer/internals/secured/RefreshingHttpsJwks.java