public static String generate(final NetworkName network) {
    if (network.getDeprecationDate().isEmpty()) {
      throw new AssertionError("Deprecation date is not set. Cannot print a deprecation message");
    }

    return FramedLogMessage.generateCentered(
        List.of(
            network.normalize()
                + " is deprecated and will be shutdown "
                + network.getDeprecationDate().get(),
            "",
            "For more details please go to",
            "https://blog.ethereum.org/2022/06/21/testnet-deprecation/"));
  }
Generate deprecation message for specified testnet network.

@param network the network
@return the deprecation message for specified network
app/src/main/java/org/hyperledger/besu/cli/NetworkDeprecationMessage.java