public Set<Object> getKeys() {
    if (operation == ServerRegionOperation.PUT_ALL) {
      Map m = (Map) arguments[0];
      return m.keySet();
    } else if (operation == ServerRegionOperation.REMOVE_ALL) {
      Collection<Object> keys = (Collection<Object>) arguments[0];
      return new HashSet(keys);
    }
    return null;
  }
@return set of keys if the operation was PUTALL or REMOVEALL; null otherwise
geode-core/src/main/java/org/apache/geode/internal/cache/tx/TransactionalOperation.java