@Override
  public int messageSpace(final int protocolVersion) {
    switch (protocolVersion) {
      case SnapVersion.V1:
        return 17;
      default:
        return 0;
    }
  }
Snap protocol messages as defined in https://github.com/ethereum/devp2p/blob/master/caps/snap.md}
ethereum/eth/src/main/java/org/hyperledger/besu/ethereum/eth/SnapProtocol.java