public static List<MilestoneDefinition> createMilestoneDefinitions(
      final MainnetProtocolSpecFactory specFactory, final GenesisConfigOptions config) {
    List<MilestoneDefinition> milestones = new ArrayList<>();
    milestones.addAll(createMainnetMilestoneDefinitions(specFactory, config));
    milestones.addAll(createClassicMilestoneDefinitions(specFactory, config));
    return milestones;
  }
Provides milestone definitions for the Ethereum Mainnet and Classic networks.
ethereum/core/src/main/java/org/hyperledger/besu/ethereum/mainnet/milestones/MilestoneDefinitions.java