@Override
  public Optional<NearestKeyValue> getNearestAfter(
      final SegmentIdentifier segmentIdentifier, final Bytes key) throws StorageException {
    return getNearest(
        key,
        k -> super.getNearestAfter(segmentIdentifier, k),
        k -> parent.getNearestAfter(segmentIdentifier, k),
        true);
  }
Constructor which takes an explicit backing map for the layered key value storage.

@param map the backing map
@param parent the parent key value storage for this layered storage.
services/kvstore/src/main/java/org/hyperledger/besu/services/kvstore/LayeredKeyValueStorage.java