public Optional<Bytes> getCode(final Address address, final Hash blockHash) {
    return fromAccount(address, blockHash, Account::getCode, Bytes.EMPTY);
  }
Retrieves the code associated with the given account at a particular block hash.

@param address The account address being queried.
@param blockHash The hash of the block to be checked.
@return The code associated with this address.
ethereum/api/src/main/java/org/hyperledger/besu/ethereum/api/query/BlockchainQueries.java