public Region getRegion() {
    return region;
  }
Return the Region that already exists which prevented region creation.

@return the Region that already exists, or null if this exception has been serialized, in which
        {@link Throwable#getMessage } will return the pathFromRoot for the region that exists.
geode-core/src/main/java/org/apache/geode/cache/RegionExistsException.java