@Override
    public Optional<Address> getAccountTrieKeyPreimage(final Bytes32 trieKey) {
      return Optional.ofNullable(preImageCache.get(trieKey)).map(Address::wrap);
    }
A caching PreImageProxy suitable for ReferenceTestWorldState which saves hashes in an unbounded
BiMap.
ethereum/core/src/main/java/org/hyperledger/besu/ethereum/trie/pathbased/bonsai/storage/BonsaiPreImageProxy.java