@Override
    public boolean isOnOrAfterMilestoneBoundary(final ProcessableBlockHeader header) {
      return Long.compareUnsigned(header.getTimestamp(), timestamp) >= 0;
    }
Associates a {@link ProtocolSpec} with a given block number or timestamp level starting point
Knows how to query the timestamp or block number of a given block header
ethereum/core/src/main/java/org/hyperledger/besu/ethereum/mainnet/ScheduledProtocolSpec.java