@Override
  public Collection values() {
    checkReadiness();
    if (!restoreSetOperationTransactionBehavior) {
      discoverJTA();
    }
    return Collections.unmodifiableSet(new ValuesSet());
  }
This method returns collection of all the values of this PartitionedRegion(locally or
remotely).

@return collection of all the values of this PartitionedRegion
geode-core/src/main/java/org/apache/geode/internal/cache/PartitionedRegion.java