default boolean exists(T config, InternalCache cache) {
    return get(config, cache) != null;
  }
Defines the behavior to realize a configuration change in the cache on a server. Created with an
object of type {@link CacheElement}, which represents the
configuration change.
geode-core/src/main/java/org/apache/geode/management/internal/configuration/realizers/ConfigurationRealizer.java