@Override
  public KeyInfo getKeyInfo(Object key, Object value, Object callbackArg) {
    final int bucketId;
    if (key == null) {
      // key is null for putAll
      bucketId = KeyInfo.UNKNOWN_BUCKET;
    } else {
      bucketId = PartitionedRegionHelper.getHashKey(this, null, key, value, callbackArg);
    }
    return new KeyInfo(key, callbackArg, bucketId);
  }
Changes the CustomExpiry for idleTimeout for values in the region

@param custom the new CustomExpiry
@return the old CustomExpiry
geode-core/src/main/java/org/apache/geode/internal/cache/PartitionedRegion.java