@Override
  public boolean exists(Region config, InternalCache cache) {
    org.apache.geode.cache.Region<Object, Object> region =
        cache.getRegion(SEPARATOR + config.getName());
    if (region == null) {
      return false;
    }

    return !region.isDestroyed();
  }
the default implementation will have the extra work of getting the runtime info which is
unnecessary. It will also have some concurrency issue if the region is being destroyed.
geode-core/src/main/java/org/apache/geode/management/internal/configuration/realizers/RegionConfigRealizer.java