public static EvmSpecVersion defaultVersion() {
    EvmSpecVersion answer = null;
    for (EvmSpecVersion version : EvmSpecVersion.values()) {
      if (version.initialHardfork.finalized()) {
        answer = version;
      }
    }
    return answer;
  }
What is the "default" version of EVM that should be made. Newer versions of Besu will adjust
this to reflect mainnet fork development.

@return the current mainnet for as of the release of this version of Besu
evm/src/main/java/org/hyperledger/besu/evm/EvmSpecVersion.java